No. XXVIII.
The Twentieth Annual Report of Her Majesty's Inspectors of Explosives very properly opens with a resume of the results of the operation of the Explosives Act of 1875 under which the inspectors hold. The growth of the trade in explosives during this time has been remarkable. Not only has the number of factories increased in the United Kingdom from 55 to 134, but a large proportion of them have been enlarged, some of them having been more than doubled in size. This growth may to some extent be measured by the increase in the number of explosives which may be made in the several factories, or by the number of factories in which each kind of explosive can be made. Thus, while the number of factories in which gunpowder or nitrate mixtures may be made has remained stationary, the number for nitroglycerine compounds has risen from one to nine, and while dynamite was the only nitroglycerine compound produced in 1876, there are no less than twelve such compounds licensed now. The factories for gun-cotton compounds, which include nearly all the smokeless powders, have risen from nine to twenty-nine. The factories for fulminate of mercury have increased from two to six, and for the various kinds of ammunition to about the same extent, while the number of fireworks factories has doubled, notwithstanding the large importations of Chinese and other oriental fireworks during this interval. The number of magazines has increased from 199 to 288. The comparison for employees is made only for ten years, the number having increased from 7484 in 1885, to 10,023 in 1895. "The number of deaths from accidents by fire or explosion in manufacture was ten only, which, although above the average for the past ten years, marks an extraordinary and most satisfactory contrast with the figures which obtained before the Act came into operation. We repeat that it should also be remembered that not only has the actual number of factories largely increased, but also, in many cases, the amount of output of an individual factory, and consequently the number of hands employed and the resulting chances of accident. Moreover, the risks attending the manufacture of wholly new explosives, to which a large proportion of the new factories are devoted, are less well known than those connected with the more familiar explosives, and, therefore, are not so easy to provide against." The total number of accidents from all causes (excluding nonfatal mining accidents with gunpowder) were 152, causing 40 deaths and injuring 167 persons, while for 1894 the accidents were 102, with 28 killed and 91 injured, and the average for ten years is 132 accidents, with 37 killed and 114.3 injured. The increase in the number reported for 1895 is in a measure due to increased facilities for collecting reports. Only one-fifth of the accidents causing death or personal injury occurred under conditions controlled by the Explosives Act, viz, during manufacture, keeping and conveyance.
It is to be regretted that these reports do not give the amount of the various explosives produced and consumed in Great Britain, as this would be a valuable criterion by which to test the working of the Act.
The complaints that the restrictions imposed by the Act fettered competition with foreign manufacturers, which were freely made in anticipation of the passage of the Act, and which were common in the early days of its administration, have of late years become extremely rare. Other countries have since enacted laws or applied regulations based in no small degree on these, and, as a general rule, of increased stringency. Of these is the Belgian law of October 8, 1894, which appeared in the Moniteur Beige of November 8, 1894, and of which the commissioners themselves say, in submitting the code, "This code is exceedingly severe, but it is rendered imperative by the exigencies of public security," and the German law, which, in many of its regulations, such as the making of cartridges, goes far beyond what is required in England. The French Committee on Explosive Substances said several years ago of the English Explosives Act: "It appears to the Committee that these wise measures ought to be initiated in France, regard being had to the differences in our institutions and our legislation."
In the operation of the Act during 1895 the following have been added to its list of authorized explosives: Dahmenite A (nitrate of ammonium, naphthalene and bichromate of potassium; the latter not to exceed 2.5 per cent.); Electronite (Nos. and 2) (No. i consisting of blasting amberite with carbonate of calcium, and No. 2 of nitrates of ammonium and potassium with wood meal); Emerald Powder (Cooppal's powder colored with the oxalate variety of malachite green); Faversham Powder (nitrate of ammonium with di-nitro-benzol, di-nitro-naphthalene, tri-nitro-naphthalene, chloride of sodium and chloride of ammonium or either of them); Pigou's Military Smokeless Powder (gun-cotton thoroughly purified and gelatinized); Pigou's Sporting Smokeless Powder (nitro-cotton, nitrate of barium and starch colored with indulin); Roburite No. 3 (nitrate of ammonium, di-nitro-benzol and chloro-naphthalene); Rosslyn Smokeless Powder No. i (nitro-cotton, nitrates of barium and potassium, or either of them, paraffin or vaseline, and starch), and Rosslyn Blastite (the same ingredients as the preceding, but in a different form), while gunpowder cartridges enclosing sealed tubes containing liquid ammonia have been treated as gunpowder cartridges pure and simple.
Although all nitro-cotton is now admitted to be explosive, and collodion cotton (except when in solution in alcohol and ether, or wet or saturated with methylated spirits and enclosed in air-tight cases) appears on the authorized list; the particular form of collodion cotton used in the manufacture of xylonite and kindred articles may be used under the following easy conditions:
"If the collodion cotton contain not more that ii.11 per cent. nitrogen, then (a) if the quantity do not exceed moo pounds, no distances need be assigned, but the building to be constructed SO far as practicable of uninflammable material, and must be screened from other buildings by a substantial fire-proof screen of such material, construction and dimensions as shall satisfy a Government Inspector; provided that the wall of the building itself, or the wall of any adjoining building, or both walls, may, with the approval of a Government Inspector, be deemed to be such screen; and (b) if the quantity exceed moo pounds, the distances to be observed from other buildings and works may be half those laid down for the corresponding quantity of guncotton, subject to such further reduction, if any, on account of the nature of the ground, intervening mounds, or screens, as in the judgment of a Government Inspector may be properly admitted."
A summary of the reports received on the use of the jelly-bag system of mixing dry cap composition are all in its favor, only four accidents, which were harmless, ,having occurred with it since 1891, while one company reports having mixed 6o tons of the composition by this means, since 1891, without accident.
Permission to send safety fuze by post was refused on the ground that it might be equally well asked for percussion caps, amorces (properly packed), time fuzes and the like, all of which are classed as explosives, and that it was best to prohibit all explosives being sent by mail.
The importation of foreign nitroglycerine compounds for 1895 was—
Blasting gelatine 15,650 pounds.
Carbonite 223,000 pounds
Dynamite 56,000 pounds
Gelatine dynamite 493,920 pounds
Matagnite gelatine 91,500 pounds
Total 880,070 pounds
This is an increase on the amount (539,802 pounds) imported in 1894, though it does not reach the average of former years. The dynamite rose from 23,000 pounds in 1894, and the matagnite gelatine has more than doubled. The number of detonators imported in 1895 was 6,981,000, as against 9,765,400 in 1894; while 496,000 pounds (248 tons) of fireworks were imported against 290 tons in 1894. A considerable portion of these importations is for re-shipment abroad.
The chemist, Dr. Dupre, reports the examination of 302 different samples, of which all but three (and all of these were fireworks) passed.
The results of the test of one sample of gun-cotton are of special interest. This sample had been manufactured at a time when the pulping of nitrated cotton had not yet been adopted, and must, therefore, have been something like 25 years old. It was contained in a half-pound square tin canister.
The canister was in several places perforated by corrosion, and all the gun-cotton in contact with the metal was stained dark reddish brown. It gave the following results on examination:
Nitro-cellulose, insoluble 95.46, heat test, one hour.
Nitro-cellulose, soluble 3.50, nitrogen, 13.2 per cent.
Mineral matter 1.04
100.00
The mineral matter was chiefly oxide of iron and sulphate of calcium. There was no carbonate of calcium or sodium. The analysis shows that this sample of gun-cotton, probably over 25 years old, is of remarkably good character, and that it has apparently improved, rather than otherwise, as regards the heat test.
Among the alterations permitted in explosives already licensed is the addition of mineral jelly to ballistite.
The heat test for gun-cotton and non-gelatinized gun-cotton preparations has been made more stringent by raising the temperature to be employed from 1500 to 170° F., the time (10 minutes) remaining as before.
The temperature for the heat test to be applied to all horny or semi-horny explosives consisting mainly of gelatinized guncotton (such as Walsrode powder), or gun-cotton and nitroglycerine (such as cordite and ballistite), has been raised to 1800 F.
Among the Accidents we note one occurring at Hayle on November 5, during the manufacture of cordite. A cylinder full of the paste had been placed in the squirting press and the pressure just applied, when the cylinder burst and a stream of fire was seen to issue from underneath the press. Through this three of the six persons present were slightly burned, while 40 pounds of cordite present in the building were set on fire, resulting in the complete destruction of the building. The pieces of the cylinder were not projected with any great violence, and all danger from them could have been prevented by a rope mantlet. The accident is believed to have been due to the heat developed by the too sudden compression of the air in the interstices of the paste, and may be averted by some arrangement for controlling the movement of the plunger.
A similar accident occurred at Waltham Abbey, April 22. The cylinder contained about 30 pounds of cordite paste. About one ounce appears to have exploded, breaking the cylinder in four pieces, and projecting two of them with some violence. The bulk of the paste fell out of the broken cylinder intact, instead of being scattered about, as in the Hayle explosion.
The various explosive accidents reported from the Eley Bros. works, where the wet process for mixing cap composition still prevails, indicates that this method is more liable than the dry process to produce a dangerously sensitive cap. There is undoubtedly a tendency in all chlorate mixtures which have been wet to form minute crystals on the surface and become unduly sensitive in consequence. The wet process may also under certain conditions leave a thin smear of composition on the walls of the cap. Yet there is no doubt that the wet process is free from certain manufacturing risks which it is impossible wholly to eliminate from the dry process.
Among the descriptions of "Foreign Explosions" we especially note those at Leeuwfontein, South Africa, November 28; Butte, Montana, January 15; Pinole, California, May 21; Parkersburg, West Virginia, June 2; and Keeken, Germany, March 19, for their magnitude, the last named being the largest explosion of explosives in transit on record, except that at Santander, November, 1893. Of additional interest is the fact that the explosives at Keeken were frozen at the time of explosion. As much data as possible is given in each case by which to determine the radius of destructive effect.
Several accidents from frozen nitroglycerine explosives are elsewhere recorded in this report.
Among the "Miscellaneous Accidents" are explosions from lignozote (ordinary japan dissolved in benzoline); ether in transit, by which a freight train was destroyed; and a chlorate of potash lozenge which was rubbed against the igniting surface of a safety-match box in the pocket of a stock broker.
After the usual good-sized list of " Outrages" and "Petroleum Accidents" comes the record of "Experiments," which were devoted to testing the degree of inflammability of magazine clothing when exposed to burning cordite or other nitro-compounds. Many materials were tried, among them lasting cloth jackets and stout woolen cloth trousers, as supplied by the Government, but the most satisfactory in every respect is "white duck" treated with the following solution:
Ammonium sulphate 8 parts.
Ammonium carbonate 2 1/2"
Boric acid 3”
Borax 1 ¾”
Water 200 "
Dissolve, then add two parts starch, stir well and boil. The fabric should be dry before steeping in this solution. This most satisfactory report closes with a description of the blowing up of the " Talcen Mawr," a rock which had been immortalized by Welsh bards, and which was estimated to contain from 125,000 to 200,000 tons of matter.
Oscar Guttmann contributes to the Jour. Soc. Chem. Ind. 16, 283-293; 1897, an article entitled "The Chemical Stability of Nitro-Compound Explosives," which discusses the "heat test" as now prescribed, and offers a new one.
The chief " nitro-compound " explosives, nitroglycerine, nitrocellulose or mixtures of these, nitro-benzene, nitro-toluene, picric acid, picrates and the like, are manufactured now-a-days so well that the only possible cause of decomposition is through the action of heat; though sometimes substances are added to them, either to neutralize any free acid present, or to modify the explosive effect, or sometimes they are subjected to mechanical treatment which affects their stability.
Various methods have been proposed to ascertain whether or not an explosive is liable to decompose at the temperatures to which it may be exposed in ordinary storage and use; all of which are based on the detection and the presence of nitrogen peroxide if it be developed in the explosive. Hess passes the vapors from the heated explosive into a solution of potassium iodide. Some subject the sample to 100-135° C. for a day or a week, the absence of red fumes being taken as an evidence of stability. Abel's heat test, using potassium-iodide-starch paper as an indicator, as modified by Dupre, is used in Great Britain, while in Germany zinc-iodide-starch paper is used.
With proper attention, there is now no difficulty in producing, by Abel's process of pulping and poaching, gun-cotton of sufficiently high stability to pass the English heat test. The practice of adding carbonate of soda, lime, magnesia and the like, is being gradually dispensed with. Guttmann believes himself to have been the first to point out that such addition is not only unnecessary, but a deception, for if real decomposition be going on in an explosive the small quantity of neutralizer added will soon be exhausted, while some of these added bodies have themselves a tendency to decompose some nitro-compounds. That a properly purified explosive will keep practically forever under ordinary circumstances of storage is exemplified by the original sample of nitroglycerine made by Sobrero in 1874, and now stored at the Nobel factory in Avigliana. That the different substances used as neutralizers act differently was shown by Dupre, who found that while practically no effect on the "heat test" resulted from adding calcium or magnesium carbonate to gelatine dynamite, sodium carbonate tended to increase the duration of the test in bad samples and decrease it in good ones. In the bad sample it neutralized the acid already present; in the good sample it tended to decompose it. Guttmann found that ammonium carbonate added to blasting gelatine caused decomposition to such a degree that the guncotton partly disappeared and the nitroglycerine sweated out from the cases so that the walls and floor of the magazine were wet with it. The ammonia, which is easily liberated from ammonium carbonate, acts on nitroglycerine, but more readily on guncotton.
The nitro-substitution compounds (picric acid, etc.) are easily purified by washing, recrystallization and washing with neutralizers, and are perfectly stable when free from acids.
Being an oily liquid, nitroglycerine is more difficult to purify, but by the use of compressed air it can be cleansed; sodium carbonate or soda in powder being added to the wash-water to neutralize the bulk of the acid, and the remaining traces being taken out by repeated washings with hot or cold water or very weak soda solution. Besides mixing the nitroglycerine more thoroughly with washing liquids, the compressed air serves to oxidize the lower " nitro-compound " generally pre§ent in impure nitroglycerine. Among obscure causes of persistent acidity in nitroglycerine Guttmann found the presence of the spongy lead sulphate, formed in the lead nitrating apparatus, to be one. Being porous, and being especially formed on the line of contact between the air and surface, it absorbs and retains the nitrous impurities, and being detached it falls into and passes off with the nitroglycerine. A minute quantity of this in the sample tested will seriously affect the heat test. Cleansing the " nitrator " corrects this. Another source of error was found due to the method of adding the soda in washing the nitroglycerine. When this is added in powder, instead of in solution, soda mud is thrown down. If some of this mud be placed on litmus paper it gives a distinct alkaline reaction, but if a drop of nitroglycerine be put on top of it and allowed to remain for a while, there will be an acid reaction at the line of contact between the nitroglycerine and the soda mud showing decomposition.
It is not to be assumed that because each of two "nitrocompounds" is stable under the heat test a mixture of them will have equal stability. Blasting gelatine is made by dissolving soluble gun-cotton in nitroglycerine by gentle heating. As some " nitro-compounds " develop nitrogen peroxide at temperatures lower than that of the official "heat test," the stability of the finished product will depend much upon the temperature at which the blasting gelatine is made and the mechanical treatment that it has undergone. The same is true with mixtures of picrates, solutions of gun-cotton in nitro-benzine, and molten masses of " nitro-compounds " of low melting points. In making smokeless powders the paste is made by prolonged treatment in kneading machines, and is frequently rolled into sheets in steam-heated rolls which reduce the duration of the heat test, since treatment at elevated temperatures produces local development of nitrogen peroxide, which then develops progressively. In making blasting gelatine the nitrogen contents of or solubility of the gun-cotton in nitroglycerine are not reliable criterions of the ability of the gun-cotton to retain nitroglycerine, as heretofore supposed.
Dynamite may be mechanically unstable through exudation. This depends on the absorptive capacity of the kieselguhr, and the temperature to which the dynamite is subjected. When too low the nitroglycerine freezes, contracts nearly one-tenth its volume, and leaves the outer layer of the absorbent, so that when thawed again it may not distribute itself uniformly through the absorbent. When too high the nitroglycerine expands, and, if the guhr was originally super-saturated, oozes out. Water also, by osmotic action, displaces the nitroglycerine. The possible effect of the heat test on explosives increases with the number of their constituents. Twelve years ago it was found that a good dynamite could not be made with a perfectly good nitroglycerine and an apparently excellent kieselguhr. Examination of the latter showed the presence of considerable amounts of aluminum sulphate, and tests proved that a small quantity of this salt decomposed nitroglycerine.
Several years ago great difficulty was found in transporting gelignite to Australia by sailing ships. It would pass the heat test in England, but fail in Australia and be condemned and destroyed. The cause was found in the wood pulp used in its manufacture. It was essential that it should be dry, and in drying it a part of it was charred, developing acetic acid and methyl alcohol. Guttmann shows that a very small quantity of acetic acid lowers the heat test, though it does not affect the stability of the explosive. When sodium carbonate is present, the methyl alcohol, as a solvent of the "nitro-compounds," accelerates their decomposition.
The smokeless powders gave the Home Office authorities much trouble, which was overcome by requiring for the Schultze class that they be dried in an oven at 120° F. and exposed to the air for two hours before trial by the heat test; and for the cordite class that they be ground in a pug-mill, sifted through a set of thin sieves, and the material retained by the second sieve used for the test.
In September, 1895, Hermann Guttler pointed out that while he could get a heat test reaction, with iodide paper, from Plastomentite, he could either get none, or only after hours of heating, from Walsrode powder, and that if he put a developed iodide paper in the tube with Walsrode powder, the brown line disappeared almost immediately. Guttmann found, as was to be expected, that this brown line disappeared if the paper was heated for five minutes in an empty test-tube at 18o° F., as such discharge of the color is a long and well-known lecture experiment. The German zinc iodide paper proved more sensitive than the English paper. He found that old Walsrode powder gave a much quicker heat reaction than a recently prepared one, and that a large variety of substances are contained in the different smokeless powders which, in his opinion, will stultify the heat test. Foremost among these are acetic ether, acetone and oils, but vaseline, aniline and other substances affect it also. The amount of solvent left in smokeless powder is variable. The greater the density the more difficult it is to drive the solvent off, so that some powders retain as much as one per cent., while others retain but a fraction of a per cent. Though the latter amount may not be apparent to the smell, yet, when the powder is ground and heated in the tube, its presence will be made evident, and if this ingredient be of the class which acts upon iodine, it will tend to make the line on the test paper disappear as the nitrogen oxide given off tends to make it appear. Consequently a powder may be in a state of decomposition and yet the solvent present may prevent the formation of the "brown line" until either the development of the nitrogen oxide has become very great, or a part of the solvent has been driven out by leakages about the stopper or glass rod. This action of acetone and castor oil Guttmann believes explains why he was unable to get a "heat test" reaction with Maxim's powder, even after a two hours' exposure at 90° C., as both these substances were present in the powder.
Besides this, iodide-starch papers made by different chemists gave different results with the same powder. A powder ground in the evening gave a longer "heat test" when tested at once than when tested next morning. Sometimes a powder that was exposed for many months gave a better "heat test" than a freshly prepared one. Coarsely ground powders gave worse "heat tests" than finely ground ones. The mill used for grinding the powders chips the powder, and, though only those grains that are retained by a certain sieve are used for the test, yet there are great differences of size whereby different quantities of the solvent may be given off. From this Guttmann concludes that the iodide heat test, as at present prescribed, is absolutely inapplicable for most of the modern smokeless powders and for some blasting explosives.
As manufacturers may suffer great pecuniary loss through having their products condemned by an unsuitable method of testing, Guttmann sought for a more reliable method, and looking over the various reagents proposed during the last forty years for the detection of small quantities of nitrogen peroxide he tried the following: Griess', a mixture of sulphanilic acid and naphthylamine in acetic acid; Plugge's, mercuric nitrate and carbolic acid; Jorrissen's fuchsine dissolved in glacial acetic acid; Vogel's rosaniline; Medola's para-amido-benzeneazodimethylaniline; Curtman's antipyrine; Kopp's diphenylamine; Frankland's sulphanilic acid and phenol; Griess' m-phenylene diamine hydrochloride.
Of these, for reasons given at length, Guttmann selected diphenylamine, and he makes the reagent and test as follows: Place 1/16 gram of diphenylamine crystals in a wide-neck flask with a ground glass stopper, add 50 cc. of dilute H2SO4 (10 cc. H2SO4: 40 cc. H2O) and place the flask in a water-bath at 500 to 55° C. At this temperature the diphenylamine will melt and at once dissolve in the sulphuric acid, when the flask should be removed from the bath, well shaken and allowed to cool. After cooling, add 50 cc. of Price's double-distilled glycerine, shake well, and keep in the dark. This solution has a strength of about 1 in 1000 by volume.
In making the test 1.5 grams of the explosive, prepared as prescribed in the English tests, is placed in the test-tube heretofore used. Strips of well-washed filter paper, or of any good chemical filter paper, 25 mm. long and m mm. wide, are attached to the hooked glass rod as usual and moistened, by applying with a clean glass rod a drop of the diphenylamine solution to the upper corners of the filter paper, so that when the two drops run together about a quarter of the filter paper is moistened. This is now put in the test-tube, which is now put in the waterbath, which has been heated to 70° C. The heat test reaction should not show in less time than fifteen minutes. It will begin with a greenish-yellow color on the moist part of the paper, and from this moment the paper should be carefully watched. After one or two minutes more a dark blue line will suddenly appear on the dividing line between the wet and dry part of the paper, and this is the point that should be taken.
The blue mark appears promptly within a few seconds, while with the iodide paper it takes sometimes as much as two minutes to obtain a well-defined brown line, and even then careful operators often have disputes as to whether the brown line exists or not. The blue mark is not as readily visible by night as by day, but it is still sufficiently clear to be detected. It is better to look at the paper with the light falling on it rather than passing through it from behind. In case of doubt a screen of filter paper behind the tube will make the blue line more readily visible. The incandescent gaslight is the best for observing with; a screen of thin light blue paper being required when the electric or ordinary gaslight is used.
It is essential that the explosive shall contain the least possible moisture, as otherwise the paper will soon become thoroughly wet, when no test can be made. The drying of explosives at temperatures above 40° C. is inadvisable, as at 450 to 50° C. traces of nitrogen peroxide are often developed which would vitiate the test. The present Home Office regulation for drying gun-cotton in an open water-oven at 120° F. is satisfactory, though it might be advisable to dry for one hour instead of fifteen minutes, but at 40° C. only. Smokeless powders should not, as a rule, be dried, as some of the ingredients are, to an extent, volatile at 40° C., while usually they do not contain an appreciable amount of moisture.
Guttmann believes that the coefficient of transmission of heat should not be neglected in these tests, and his experimental data justify his view. In addition he experimentally investigated the relation between the temperature to which a sample is exposed and the time within which the diphenylamine reaction shows itself, and exhibits the results for five bodies in a graphic manner, giving also the formulas by which such curves may be charted. From these he concludes that it will scarcely be sufficient to say that an explosive must withstand a certain temperature for a certain number of minutes to be reasonably safe, for it is possible to conceive a case where an explosive has a constant approaching zero, and whose decomposition at increased temperatures may require wide intervals of time; while, on the other hand, one may have to wait a rather long time to start decomposition, and yet when once started it may develop rapidly.
Referring to his results, Guttmann says: " Considering that. . . it takes 8 1/2 minutes to heat the contents of a test-tube to 70° C., it may cause surprise that the constant of some powders on the diagram is 5 minutes, and that of gun-cotton 3 minutes only; but this is due to the fact that with them decomposition starts at a lower temperature than 8o° C. The heat, test value of an explosive will, therefore, be the inferior the more its constant is below the time required for obtaining equilibrium between the outer and inner temperatures of the test-tube, and it will be advisable to fix a minimum limit for the constant of say 5 minutes."
The author does not claim that his method meets all objections to the "heat test." There are still vagaries encountered in its use, and it will still be empirical, but the beneficial effects thus far resulting from the "heat test" prove it to be a necessity.
The paper aroused an extended discussion in which many authorities took part, and which is as valuable as the paper itself. These speakers, as a rule, had not encountered the difficulties in the use of the iodide starch paper that Guttmann had, and Dr. Dupre did not express himself as ready to abandon it for Guttmann's. Mr. Otto Hehner pointed out that while the iodide-starch was a reagent for nitrous compounds, the diphenylamine was a reagent for nitrites or nitrates, the latter of which cannot be detected by the iodide test, and it was therefore obvious that in many cases the two tests could not give the same results because they did not apply to the same thing.
In the Jour. Am. Chem. Soc. 19, 156-170; 1897, E. C. Woodruff gives the results of his study of the " Color Reactions of Nitric and Chloric Acids with Certain Aromatic Bodies," in which he sought to find some new practical tests for nitric and chloric acids, more especially such as would differentiate the two, both in.mixtures and separately. The latter object was repeatedly attained. The former was more difficult, because, in general, chloric acid produces a darker color reaction than nitric, in some few cases sufficiently so as to indicate chlorates in the presence of nitrates; in most cases enough darker to completely mask the nitrate effect; while in some cases the effects were indistinguishable. Still, two methods are given whereby the nitrate effect can be made to predominate, and one that, properly manipulated, accomplishes the desired result very well. The reagent used is dimethylaniline with paratoluidine and sulphuric acid. It gives a colorless solution that keeps well and is an absolute test for nitrates.
The author experimented with a large number of phenols, cresols, oxyacids, amines and so on, and gives his results. Speaking of diphenylamine, he says that "four per cent, gave a light green solution which gradually darkened. This makes a fairly delicate test for nitrates, but there are several serious faults in its workings. First, it gives a rather poorly keeping solution. Second, it will not bear dilution or neutralization. . . . Third, it must be kept cool, as heat alone, even the heat generated by adding a drop of distilled water to two or three of the solution, may give the color supposedly due to a nitrate. Heating changes it first to green, then to a blue, and finally to dense black flakes in a colorless liquid in which water no longer produces a muddy brown precipitate as before."
Under the title "Some Recent Improvements in Smokeless Powder Compounds and in Processes of Manufacture," Jour. Soc. Chem. Ind. 16, 495-499; 1897, Hudson Maxim gives a general review of the composition and properties of smokeless powders, and, speaking of the Maxim-Schiipphaus powders, says a method patented by us for producing a smokeless powder of this character is substantially as follows: Trinitro-cellulose is made into papers or a thin pulp board, which is subjected to a bath made of soluble pyroxyline dissolved in a solvent which is not a solvent of the trinitro-cellulose. In other words, the guncotton paper is sized in a collodion bath, which bath may or may not contain nitroglycerine; the excess of the bath being removed, sheets of the material are placed upon one another and pressed together, whereby a body of any desired thickness is built up. The mass is then placed in a suitable die or mold and multi-perforated in a manner explained further on. The hardness and density of the product may be varied within wide limits by varying the consistency of the bath or the amount of size left in the paper, and also by varying the compression. The material may then be cut into strips approximating in length the powder chamber of the gun, or any length desired. Before being perforated a sheet of unnitrated paper may be affixed to two surfaces of the body, whereby they will be to a great extent protected from ignition during the early stages of combustion in the gun, thus causing a greater degree of combustion to take place within the perforations. Or, the body of material may be multi-perforated and dried, and then coated with any suitable substance which will delay ignition of the surface.
The old black and brown powders being but compressed mechanical mixtures, were unsuited to that special form of grain consistent with the production of the highest ballistic results. With the introduction of smokeless powders, made of a dense and tenacious colloid of gun-cotton, or of gun-cotton and nitroglycerine, it became possible, by a special system of multi-perforations, to produce a grain which will burn in the desired manner, although this result has not been easy of attainment. Trinitro-cellulose requires a large quantity of solvent, not only to dissolve it, but even to render it plastic, and rods or grains formed of it are exceedingly difficult to dry without warping and cracking to pieces, and it is difficult to make it take and retain the exact shape of the forming die. Consequently, unless a very large percentage of nitroglycerine be employed, a composition must be produced which allows working in a much drier state than ever heretofore attempted, in order that the plastic mass shall retain the shape given it by the die in all its geometric details. All this calls for special tools, special processes, and a special compound.
Two smokeless powder compounds are employed by him; one consisting of a compound of nitroglycerine and mixed gun-cottons, the other of mixed gun-cottons without nitroglycerine. The first is made by mixing together in a kneading machine, at a temperature of about 1200 F., 8o pounds of trinitrocellulose of about 13.3 per cent, nitrogen, with 8 pounds of gelatine-pyroxyline of 12 per cent. nitrogen (and soluble in nitroglycerine below 100° F.), 12 pounds of nitroglycerine and 35 pounds of pure anhydrous acetone, adding thereto 1 pound of pure urea dissolved in pure methyl alcohol. The mixture is worked in the kneading machine for about an hour at a temperature of about 120° F., heated by means of a water-bath. The mealy mass is then passed between cold rolls and formed into rough sheets, which are then converted into smooth sheets by Passing between slightly warmed rolls. The proper consistency for the mass is easily recognized by the experienced workman by the sense of touch, but the amount of solvent retained may also be easily ascertained by weighing from time to time. Only from 15 to 20 per cent. of solvent should be retained when the compound is ready for stuffing or molding into grains.
The smooth sheets are compactly wound about one another to form a roll of the diameter of the press cylinder, the ends preferably being trimmed. The press is kept warm by means of a water-jacket having a temperature of about 1200 F. The press being filled, the cylinder is preferably exhausted of the air within the spaces unfilled by the powder, and the mass pressed hard against the head to solidify it. The forming die is now affixed and the compound forced through it at a pressure of from 3000 to 4000 pounds per square inch, emerging in the shape of multi-perforated cylinders. The smaller the grain the softer should the material be and the higher the pressure required to force it out. The rods are cut into grains about 3 diameters long, placed on shelves in a drying-room, and when partly dried finished in a vacuum.
In the other composition 8o parts of trinitro-cellulose, 19 ½ parts of gelatin-pyroxyline and ½ per cent, of urea are used. Owing to the absence of nitroglycerine, which facilitates the molding operations, slightly more solvent is left in the material before pressing. It is impossible to evaporate the last trace of solvent from either of the compounds, "but as the quantity remains forever constant, and never escapes, it does no harm."
The peculiar influence of urea is well illustrated by its use in the manufacture of celluloid, such as photographic films, which, in case they are cut from a block of compressed material, and not made by flowing a comparatively thin solution on glass plates, or by an equivalent method, could not be produced without the use of this substance, as the temperature to which it is necessary to subject the material causes such slight decomposition as to discolor the product. Urea counteracts this by neutralizing the nitrous acid as fast as it is formed. Urea has the further advantage that it is decomposed by nitrous acid into carbon dioxide, water and nitrogen, leaving no solid product behind, while it is not an active alkali and its presence has no effect whatever upon the nitro-compounds with which it is combined.
When soluble pyroxyline is combined with trinitro-cellulose in suitable proportion it has the peculiar effect of rendering the compound plastic and enabling it to be molded with very much less solvent under the influence of an elevated temperature. This effect resembles that produced by camphor combined with celluloid pyroxylin. It furthermore renders the final product more tenacious and less liable to crack.
This is followed by illustrations, with descriptions, of a large number of different forms of perforated grains. No novelty seems to be claimed for them except " a rod or strip of powder having transverse perforations as a new article of manufacture."
In the discussion Mr. McNab observed that Mr. Maxwell Lyte had, about 1868-69, introduced a smokeless powder in France which closely resembled the form described by Mr. Maxim. While Dr. Dupre said that the use of urea was a practice which he had always set his face against, as it was equivalent to, say, adding boric acid to milk to mask a want of cleanliness or of honesty in the milk trade. If a powder were well made it ought to stand without urea or any other masking body. It appeared to him that Mr. Maxim wanted to produce a powder that burnt more rapidly as combustion proceeded. The greater the pressure the more rapid was the combustion, and no peculiar shape of the pellet was needed to ensure this.
In the Jour. Am. Chem. Soc. 19, 388-389; 1897, C. C. Parsons describes a "Method of Drying Sensitive Organic Substances," which he has successfully employed in drying wood-paper pulp in some investigations in nitrating it for a smokeless powder. The process consists in completely immersing a weighed portion of the substance to be dried in about six times its weight of oil in an evaporating dish. The dish containing the oil is placed in a drying closet kept at 2400 until the oil has attained this temperature, when it should be weighed and the weighed substance is then immersed in it. There is a slight effervescence during this operation, which is the greater the larger the amount of moisture present. The whole is returned to the closet for a few minutes and then weighed again, and this is repeated to constant weight. The loss is moisture. The oil prescribed is what is commercially called a straight paraffin oil, free from animal or vegetable oils or fats or foreign mineral substances, Perfectly neutral, 0.92 sp. gr. (22.050 B.), 435° flash test, 500° fire test, and about 55o° B. P. The object of the high fire test is to ensure the oils being so free from volatile matter that none will be carried off with the moisture of the substance. The oil must be heated in advance, as it absorbs moisture from the air when exposed.
We have noted already the danger of explosion from the contact of sodium peroxide * and combustible agents as proved by Dr. A. Dupre. In the Jour. Soc. Chem. Ind. 16, 492-494; 1897, in "A Note on a Possible Source of Danger of Fire during the Transport of Barium Peroxide," he shows that a mixture of wood-meal and barium peroxide inflames when struck by a two-pound steel weight falling 40 inches upon a steel anvil or by a glancing blow with a wooden broomstick.
Mr. G. E. Barton presents in the Jour. Am. Chem. Soc. 19, 500-509; 1897, an admirable article, "On the Manufacture of Dynamite." In our review of Guttmann's "Manufacture of Explosives," f we have referred to his failure to give the American practice in this manufacture. Mr. Barton's paper supplies this deficiency. It may also be read in connection with description of the Adeer factory referred to below.
William H. Krug and J. E. Blomen give, in the Jour. Am. Chem. Soc. 19, 532-542; 1897, the results of their laboratory experiments on the "Commercial Preparation of Nitro-naphthalenes." The paper opens with some statements regarding the commercial uses of the nitro-naphthalenes which include many instances of proposed use that have never gone into practice. The authors give the results of many experiments made to nitrate naphthalene, and find that it is impossible under the conditions existing to prepare nitro-naphthalenes from a-naphthalene-sulphonic acid; that nitro-naphthalenes are best prepared by treating naphthalene with a mixture of sulphuric and nitric acids; that the highest yield is obtained when an excess of sulphuric acid is used; that the degree of nitration, as characterized by the melting point, increases with the amount of sulphuric acid present, though an excess has the opposite effect.
To obtain nitro-naphthalenes for commercial purposes it is best to use nitric acid of 36° B. The amount of sulphuric acid to be used varies with the nitration degree desired, and ranges from 4: 1 (nitric: sulphuric) for low melting products, to 3:2 for the higher derivatives. Too large an excess must be avoided, as it chars the product and produces a tarry useless end product. In all cases the product of these processes is a mixture of different nitro-naphthalenes.
"The great Dynamite Factory at Adeer " is the title of a popular illustrated article published by H. J. W. Dam in McClure's Magazine 9, 823-836; Aug., 1897. 'The article is jauntily written and somewhat misleading, but from it we gather that the works contain 450 separate structures, covering 400 of the 600 acres owned by the Nobel's Explosive Co. at this place; that 200 girls and 1100 men are employed in the factory; that the nitrating charge is 1.5 tons of sulphuric and i ton of nitric acid to 700 pounds of glycerine, giving a yield of 1500 pounds of nitroglycerine in 55 minutes running time, the lead convertor with compressed air being used; that all persons entering the "danger area" are rigidly and repeatedly searched, and that all metallic objects—watch, money, penknife, scaripin, match-case, matches, and keys—are taken from one, while the women are forbidden wearing pins, hairpins, shoe buttons or metal pegs in their shoes or carrying knitting, crochet or other needles; that the employees in the danger area are conspicuously uniformed, nitrators in scarlet, carriers of explosives in dark blue, smokeless powder men in light blue, cartridge girls in dark blue; that the constant absorption of the nitroglycerine stimulates the amorous tendencies of the employees; that magazine shoes of rubber or leather must be worn in every danger house; that the dynamite made here contains about one pound of carbonate of ammonia to twenty-five of kieselguhr and seventy-five of nitro-glycerine; that special magazines are pro vided for testing the behavior of the various explosives during exposure for long periods to high and low temperatures; and that thirty thousand tons of dynamite have thus far been transported on English and Continental railways without an accident. The site of the factory, on a barren waste of sand-dunes, stretching for one and three-quarter miles along the sea, was selected by Mr. Nobel in 1871.
Arms and Explosives 5, 151; 1897, in its report of the annual general meeting of the Nobel-Dynamite Trust Co., Ltd., says that the chairman stated that their trade with Mexico was threatened by the United States factories, and "in order to protect this trade they were considering the advisability of establishing factories both in the east and the west of the United States." The New York Herald recently records the purchase of upwards of 600 acres of land in Middlesex county, N. J., for this purpose, where a factory is to be erected which it is expected will give employment to upwards of moo men.
Through the courtesy of Lieut. W. R. Quinan we are in receipt of the following interesting "Account of an Explosion" which occurred September 1, 1896, at the California Powder Works, Pinole, California:
"On September 1, about 1.05 p. m., there was a disastrous explosion at these works, resulting in the killing of four white men and eight Chinamen, the destruction of the new nitroglycerine house, the nitroglycerine storehouse, the mixing house, and the usual damage to many other buildings. The nitroglycerine house and storehouse were part of the new works recently built at great expense to the company. Of this plant, the ammonia refrigerating plant and acid cooling house escaped without serious injury. These new works had only been running three days.
"The trouble originated in the nitroglycerine house. Some buckets of nitroglycerine were drawn by the workmen from a waste tank in the basement of this house and brought up to the wash-tank floor and placed on a platform built around the wash-tanks. It was left there a few minutes preparatory to dumping it into the wash-tanks. Water was being drawn into these tanks for the purpose. While themen were waiting for the tanks to fill—not more than a minute, some of them say—the nitroglycerine in the buckets decomposed spontaneously, but without immediate explosion. There was no other nitroglycerine stored in the house at the time. Two charges were still in the mixers, about ready for discharge. There were four men in the house. The foreman, William Ray, was in charge of the mixers, the other three were below on the wash-tank floor, where they had just been engaged in bringing up the buckets. All the men ran when they saw the evolution of fumes from the buckets. Exactly what took place can only be guessed at in detail, but this seems about the course of events: The decomposition in the buckets was accompanied with a puff, which probably scattered the fuming oil into the scale or weighing tank, thence into the filter tank below, thence it followed a rubber-lined V-gutter to the storehouse 250 feet distant. The switch was still in place in this house, and the decomposition was communicated to the remnant of a charge, probably about 600 pounds, still in one of the store tanks. A stream was running at the time from this tank in a V-gutter or flume to the mixing house, about 1400 feet distant. The decomposition having reached a body of the liquid, an explosion took place, which was transmitted almost instantly to the mixing house, destroying the flume on the way.
"All the men killed were at the mixing house. Three out of the four white men were caught by an unlucky chance. Two were on the 'supply car,' engaged in delivering nitre at the rear. Our track scales being out of order, they were weighing it on a portable scales brought from the warehouse, which made them a quarter of an hour later than usual on that trip. Crater, the foreman of the packing house, had just come to give an order for powder in time to meet his death.
"A few minutes, not more than two at most, after this explosion, the mixers in the nitroglycerine house exploded, destroying everything connected with that building except some sheds covering the outside waste tanks at the foot of the hill. This explosion probably came about in this way: The steam-pipe supplying the engine was broken by the explosion at the storehouse and the machinery was stopped. Fresh glycerine may have run into the mixers from above, or fire may have reached them from the decomposing oil below.
"This explosion differs from most in this: the men who saw the trouble begin lived to tell the tale. This was due to a feature in the new works. As fast as the nitroglycerine was made, purified and filtered, it was run away to the storehouse. If there had been any quantity in the house all the men would probably have been killed and we should have had another mystery with a dozen plausible theories, all of which would have been wrong.
"We have learned a valuable, if disheartening, lesson. It is that the nitroglycerine collected from the waste tanks is much more dangerous than ordinarily believed. The plan of handling it in buckets is the usual one in factories. We were not blind to its dangers, and took precautions not in general use, to purify it to a certain extent before it was drawn from the waste tanks. Its sensitiveness is no doubt due to an excess of impurities derived from the wash-water.
"When the trouble started, the conduit leading from the nitroglycerine to the storehouse was fairly drained. It was about time for the switch in the latter building to be turned. This was a long pivoted trough delivering into a tank of water when out of place. The man on this duty was detained a few moments too long in handling the buckets. If the switch had been broken, there is good reason to think that no serious harm would have resulted from the decomposition in the buckets.
"It is well to note as having a possible bearing on the cause of the trouble, that the quantity of nitroglycerine in the waste tank was unusually large. There were ten buckets of the stuff drawn off and carried up to the wash-tank floor. Nothing unusual was noticed in doing this. One of the men remarked that it was uncommonly clear and free from slums. The quantity was large for this reason: In addition to the usual quantity carried over mechanically from the wash-tanks and a little run down from the second separation, the nitroglycerine collected from the refrigeration of the waste acids at the cooling house was also run down into this tank as well as the wash-waters. This nitroglycerine was regarded with some suspicion, but it was given three careful washings in a lead wash-tank before it was allowed to run down.
"In regard to our waste and catchment tanks, we had a very elaborate system. Besides the one in the basement, from which the sensitive oil was drawn, we had one at the acid cooling house and two at the foot of the hill below the nitroglycerine house. These escaped, though they had quite a quantity of oil in them. They were all built on the same pattern. Each tank was lead-lined, twelve feet long inside, and drained to one corner. Each tank was divided into four compartments by heavy. Lead curtains hanging down within a few inches of the bottom. In each compartment there was an air jet to keep the bottom liquid agitated. At the lowest point of the tank a jet of fresh water was introduced to produce a circulation and wash out any acid that might be present. Each tank had an overflow at the end. In regard to the chance of an accumulation of acid in the waste tank, this was rendered impossible: Water was flowing through the tank constantly, and the strong soda from the wash-tanks had to pass through the catchments going down under the partitions in close contact with the bottom liquid which was being stirred by the air-jets. The arrangement was intended to give the waste nitroglycerine a preliminary washing before it was drawn off. That it should have been so prone to decomposition in spite of all the care taken is very strange.
"The simplest view to take of the matter is this: Nitroglycerine, as the immediate product of the nitration of glycerine by mixed acids, is a complex substance. It probably varies considerably in composition from the presence of varying quantities of the lower nitrates and other impurities (some of which are unstable), depending upon the quality of the acids and the glycerine. With these natural and unnatural impurities adhering to it its behavior is very uncertain. Fortunately the impurities are soluble in fresh or alkaline water, and can be removed, leaving a liquid which is fairly stable and well defined in properties.
"The waste nitroglycerine collected in the catchments consists of that carried away mechanically in washing, and also of that precipitated by neutralizing the acid water, as both acid and alkaline waters dissolve more than fresh water or neutral solutions, and this waste nitroglycerine is especially dangerous, because it contains an excess of impurities from contact and mixture with the wash-waters.
"We were using an American glycerine—a brand which up to the time we had regarded as a standard in purity and good behavior. For obvious reasons I do not mention the name of the manufacturer.
"This explosion had several curious features. An explosion of nitroglycerine proper is free from fire; that, for instance, in the storehouse, a building which had double walls and floors packed with sawdust, .though it made match-wood of the building, did not leave a scorched chip behind it. That in the mixers was very different. These were steel vessels with mechanical stirrers. In the short time intervening between the stopping of the stirrers and the explosion the oil had only partially separated from the acids. The explosion was violent enough to destroy the building, but a large portion of the nitroglycerine was an emulsion in the acids and escaped explosion, being scattered with the acids over an immense space. The breeze carried the magnificent yellow cloud toward the north. Grass fires were started in the stubble at a hundred different points within a radius of half a mile. For the first hour or two after the explosion the energies of our men were absorbed in fighting these fires. This was not dangerous work, except in the vicinity of the sheds covering the waste tanks still left standing at the bottom of the hill, near the site of the nitroglycerine house. It was rightly suspected that these tanks contained nitroglycerine (we recovered about 250 pounds from them next day). The fire was burning fiercely near them, and had already attacked the shed covering the last catchment—a small tank about twelve feet beyond the large waste tanks. The flume connecting this with the waste tanks was also on fire. Every few minutes there would be a report like a pistol shot, showing that the fire was coming in contact with small quantities of the liquid. In spite of the danger, some of our men were hastening to the rescue of the waste tanks, when the small tank exploded and did the work for them. The water in the tank was scattered around, and this, with the blast, completely extinguished the stubble, the flume was blown away, and although the large shed was badly wrecked, the waste tanks with their dangerous contents were saved. This is one of the rare instances in which a small explosion prevented a larger and a more serious one."
A profusely illustrated article by Framley Steelcroft in the Strand Mag. 73, 498-506; May, 1897, entitled "Explosives,' gives brief popular accounts of some among the more extensive explosions which have occurred. Perhaps the most interesting among the pictures given are the photographs of the Johannesburg explosion of February 10, 1896, and that of the great plume of smoke from the Antwerp explosion of September 6, 1889.
An editorial of the Eng. and Mining Jour. 64, 242; 1897, on "Magazines for Explosives in Coal Mines," states that "the mining laws of most countries forbid the storage of explosives in magazines directly connected with the underground workings of collieries, though a few countries permit a small supply to be kept in such places. Thus the Austrian regulations permit 100kilograms, but the magazines must be at least 100 meters from any gallery or shaft through which persons are passing. In Saxony depots to contain 75 kilograms are allowed not less than 50 meters from shafts and 10 meters from galleries, while larger amounts may be stored according to regulations prescribed specifically by the mining authorities. According to the French and Belgian laws, only enough explosives for a single day's work may be taken into the mine. Great Britain and many of her colonies have similar laws, and the anthracite and bituminous laws of the State of Pennsylvania are not in this respect essentially different from the more stringent of the European.
"Some of the French colliery managers, however, have desired to go further than the most liberal allowances in other countries, and several years ago made application to the Minister de Travaux for permission to store underground as much as 2000 kilograms of explosives. This application was referred to the Commission du Grisou, and under its direction numerous experiments have been carried out during the past four years to determine to what extent this practice might be safely allowed. M. Ledoux, Ingenieur en chef des Mines, has recently made a report on the subject to the Commission du Grisou, which is published in Vol. XI. of the Annales des Mines, 1897.
"The existence underground of large masses of high explosives which are likely to be ignited involves a great number of problems. In the opinion of the French Commission which studied them, the dangers resulting from the invasion into the mine workings of the vast volume of gases of an explosion were most grave. It was conceived, however, that these dangers might be obviated by the interposition of a buffer to work automatically between the magazine and the main gallery of the mine. A system was devised, therefore, whereby in case of explosion a stopper fitting tightly like a piston in the connecting drift would be thrown by an explosion against an annular shoulder, thereby sealing the drift and confining the expanded gases. A series of experiments performed on a small scale proved that this device would work satisfactorily, but the Commission would not endorse it unreservedly until a test on an actual working scale should be made. The interest of the Comite Central des Houllieres de France and the Cie. de Blanzy in the matter enabled the Commission to make the desired experiments at Blanzy in December, 1895. A charge of 500 kilograms of 75 per cent. dynamite, enclosed in a gallery of 10 meters length and 5 meters square in section, so that the density of the charging was as I: ioo, was exploded. The buffer, cylindrical in shape, was 1.5 meters in diameter and 1.5 meters long. It was built up of two-thirds cardboard and one-third of wood. It was thrown back against an annular seat .25 meter wide. The chamber was 20 meters below the surface and was approached by an adit so meters long. The experiment was successful in every respect. No effect was observable beyond a dull rumbling sound, and no gas apparently was projected into the gallery of access.
"The Commission du Grisou has now laid down the following rules under which large quantities of explosives may be stored underground. Black powder is not permitted; caps cannot be kept in the same magazine with the explosives; boxes of explosives must be opened in a special chamber at least 20 meters from the magazine, and never in the latter. The illumination of the magazine must be exclusively by safety or electric lamps; boxes of explosives must be placed on shelves or benches, and never superposed; the quantity of explosive must be governed by the size of the magazine, so that the density of charge shall not exceed 1:100; good ventilation of the magazine is indispensable.
"The arrangement of the entries of the magazine, position of the magazine with respect to the surface and the working galleries of the mine, and the proper construction of the automatic buffer are described at considerable length; for these details reference should be made to the original paper.
"As to the charge-density, which, according to the commission, should not exceed 1:200, it is necessary to explain that this is worked out from the subjoined formula 1, while 2 gives the pressure produced by the explosion of a given weight of explosive.
"In these formulae r is the weight of the explosive in kilograms and V the volume of the chamber in liters, while f and a are coefficients depending upon the explosive. Thus in a chamber 5 meters square in section, containing 25 kilograms of dynamite in a box of 0.33 meter long, the volume V is 5.0 X 0.33 1.65 cubic meters = 1650 liters; and the charge-density, according to the formula, is 25 ÷ 1650 = 0.01515. If f =9.36o and a = 0.709, the pressure of an explosion in this case will not exceed 142 kilograms per square centimeter, while if the charge-density were I: 2 the pressure would be 7250 kilograms. With this disposition the pressure is independent of the quantity of explosive in the magazine. The length of the magazine would be equal to C ÷ 75, in which C is the weight of the explosive, or for 2000 kilograms about 27 meters would be required.
"The position of the powder magazine is an important question, but the arrangements prescribed by the French commission for safety when it is located underground are so elaborate and expensive that it is doubtful if any besides managers of very large collieries will care to adopt them, notwithstanding the obvious advantages that are to be gained from storing explosives in this manner.
"In this connection, however, it is not out of place to refer to the carelessness with which dynamite is often stored underground in metal mines in States of this country where there are no regulations on the subject. There are numerous instances where the magazine is a small chamber opened from a main working gallery, and separated from it by nothing but a light door, not always tight, while within it the explosive is stored and handled with a carelessness that is appalling. That there are not more serious accidents from this source is doubtless because the practice is not very general, and prevails usually only in small mines where seldom more than a small amount of powder is on hand at any one time. There is no excuse, however, for such an accident as that at the Belgian mine at Leadville, Col., in September, 1895, where six men were killed and four more were injured. The supply of powder at this mine, kept in an underground magazine, exploded, the precise cause of the explosion being unknown, and caused a fall of rock which imprisoned the gases of the powder, thereby suffocating six of the gang of men who were at work boo feet from the magazine."
The exports of explosives from Germany according to U. S. Consular Reports 53, 253; March, 1897, were as follows:
In spite of the closest competition, this year's business will be better than last year's. Sporting powder has hardly held its own, owing to the fact that there is a decrease in the world's demand for this article, yet German sporting cartridges, especially those which are loaded with smokeless powder, are in large demand. The explosives go in largest quantity to South Africa (to the Cape and Transvaal), and then come, in the order named, Russia, England, Mexico, Chile, Australia, Japan, China, Denmark, and Sweden. The former falling off in sales due to the law forbidding the use of explosives in coal mines is now being made up by the sale of patented (nitro-substitution) explosives, in which the danger from use has been reduced to a minimum.
In the U. S. Consular Reports 52, 574-576; December, 1896, the price of 75 per cent. dynamite in Cornwall is given as $291.90, and in the west of Scotland $324.97 per ton of 2000 pounds. The price per kilogram (220 pounds) in Hamburg was $68.56 in 1893; $75.32 in 1894, and $61.10 in 1895.
As one of a series of articles on the Witwatersrand gold-field and its workings, Mr. W. Y. Campbell gives in the Eng. And Mining Jour. 64, 190; 1897, an account of the "Mining Explosives in the Transvaal."
"The consumption of explosives in the Transvaal is broadly 200,000 cases per annum. A case is supposed to contain 50 pounds net. The consumption grows daily with the growth of the industry. In the infancy of the gold industry, less than ten years back, a monopoly was granted by the Pretoria government to a shrewd man from Hamburg. The object of the government was incidentally to sell local explosives to the mines, but principally to manufacture locally gunpowder and cartridges for its use and to be independent of imports through British ports. The object of the concessionaire was to make money. The result has been that he has become a millionaire by virtue of his shrewdly worded and shrewdly worked concession, but neither the government nor the industry has ever had a single pound of powder or of dynamite produced locally. At one time the concession was canceled, but a new concession, differently worded, was obtained, and this industry, which has some eleven years to run, embodies a monopoly in the manufacture of explosives and a monopoly of handling and selling.
"These prices are net at depot; freight, and therefore total cost, varies with the distance of consumers from depot. Blasting gelatine forms 6o per cent, of the total consumption.
"The Transvaal is the finest market in the world for mining explosives, therefore, and all the world's manufacturers have been eager to compete, but in vain, as the Nobel group is in Possession under the government grant and fixes prices its own way. The mine owners have repeatedly proved that with free trade their explosives would not cost much more than $11.40 a case, against the present average cost of $24.
"The costs per ton mined vary from 25 to 75 cents, while in other parts of the world isolated mines show 10 to 25 cents; 10 cents is the Alaska-Treadwell figure, and that is an isolated mine in remote Alaska. The special levy made by this monopoly on the industry here probably reached a total of $6,250,000 up to the end of 1896. The charge for 1897 will be $2,5oo,000 more than it would be with free competition, subject only to police and safety regulations.
"The consumption of dynamite, of course, varies per foot driven or sunk, or per ton raised, in the various mines with the various rocks dealt with. The cost of explosives per ton mined varies from 32 to 84 cents in the gold mines, and from JO to 30 cents in the coal mines; gunpowder for the coal mines and other explosives for gold and coal mines are also barred entry into the State; and scientific advances and improvements in mining explosives are not allowed to benefit these mining ventures, unless the monopolists introduce them.
"The above is the mine owners' view and experience, but the monopolists claim that there is no such thing as 'free trade in mining explosives' outside the United States.
"They say that the Alaska-Treadwell figures are useless, for they are for a low-grade explosive that would not work in the Rand quartzites. They have spent $4,500,000 cash in building a new factory in the Transvaal, and for that risk and expenditure they claim a right to a monopoly. The mine owners retort that they want to buy all mining materials in the best and freest markets, and they are prepared for cancellation of the contract under fair compensation and taking it over as a mines factory on a co-operative system, selling out at cost price. The fight is ten years old and no end in sight. Doubtless, owing to the very intensity of the economic evil, a remedy will ensue soon; probably the government will buy out the concessionaires and content itself with police supervision of explosives. Then the mines can have a co-operative factory or buy in the cheapest and best markets.
"The following figures of. dynamite costs for the year 1896 in one of the best-managed deep-level mines are of interest. During 1896, 833,392 cubic feet of rock were blasted; 64,100 tons of rock were removed, and 10,885 lineal feet of driving and sinking completed. Dynamite cost per cubic foot blasted, 8.8 cents; per ton of rock removed, $1.15; per foot lineal, $6.85. The work done was the development usual in getting at ore and exposing it by levels."
The Eng. and Mining Jour. 64, 244; 1897, says, regarding the "Dynamite Manufacture in British Columbia ": "There are three establishments in this province where explosives are manufactured for mining purposes. The Hamilton Powder Company, of Montreal, has works at Northfield, near Nanaimo, and the Giant Powder Company, of San Francisco, Cal., has works at Cadboro Bay, a few miles from Victoria. A third and small plant is making dynamite near Balfour, near the entrance to the west arm of Kootenay Lake. At Victoria sulphuric, nitric and hydrochloric acids are being made by the Victoria Chemical Works, which supply the powder manufacturers."
The important service which the late Alfred Nobel rendered in the development of modern explosives makes it appropriate that a brief mention, at least, of his life and work should be recorded in these Notes. We are indebted to the courtesy of the well-known Ingenieur-Conseil P. F. Chalon for a copy of Le Temps of February 18, 1897, which contains a romantic account of Nobel's life, with an attempted analysis of his character, together with much private information. We find also a somewhat extended biography of Nobel, with a portrait of him, in Arms and Explosives 5, 54-55; 1897, while the current press has given much regarding him.
From these sources we gather that Alfred Nobel was born of Swedish parents in Stockholm, October 21, 1833, being the third of four sons. Shortly after Alfred's birth his father moved to St. Petersburg, where he manufactured gunpowder for the Russian government, invented a torpedo and erected the engineering works which have since become well-known for the small arms and agricultural implements produced in them.
Alfred Nobel was educated as an engineer and chemist, his studies being carried on in Russia, Sweden and England. His linguistic attainments were extensive. He was an omnivorous reader, and took a lively interest in the progress of science, being especially devoted to chemistry and to social science.
He began the commercial manufacture of nitroglycerine in Sweden in 1862. Notwithstanding the extreme hazard attending this enterprise; that his younger brother was killed by an explosion at these works not long after their establishment; that the manager of his newer works at Krummel, near Hamburg, was killed in 1864; that numerous other disasters occurred; and that, as a result of these accidents, the transportation and use of the explosive were interdicted by law, Nobel persisted in his investigations by which to perfect the processes of manufacture and purification and the methods of transportation and use, and eventually achieved such success that factories for the manufacture of nitroglycerine are now established in all parts of the world and the output has risen from ii tons per annum in 1867 to over 15,000 tons per annum to-day.
His first patent for "a mixture of ordinary gunpowder with nitroglycerine" was taken out in 1863. He invented "Dynamite," in which the nitroglycerine was absorbed in and retained by a porous solid, like infusorial silica, in 1866. In 1875 he invented "Blasting Gelatine," in which the nitroglycerine is incorporated with soluble gun-cotton to form a plastic, jelly-like mass, and in 1887 he invented " Ballistite," which is formed from the same materials as the preceding one, but in which the soluble gun-cotton is in such large proportions that the product is a solid celluloid-like body which burns, but does not detonate, and which is therefore used as a propellant. With these as bases he formed many mixtures adapted to special purposes.
These, with the discovery of the method of firing by detonation, are the more notable among the many achievements of this daring and resourceful man. There seems to be little record of his writings, but we note "Les explosifs modernes," which was delivered as a lecture before the Society of Arts, London, May 21, 1875, and "A bas les armes," which has been translated into several languages.
It is a pleasure to relate that he secured a well-merited reward for his enterprise and application, and that from his inventions in explosives and his association with the firm of Nobel Brothers & Company in the development of the petroleum fields of Russia he accumulated an enormous fortune.
He died December 10, 1896, at his villa at San Remo, and when his will was opened he astonished the world by his munificence and the novel uses to which his bequests were to be put. This is best described in the following extracts from the report of Minister Ferguson, published in U. S. Consular Reports 54, [201], 330-331; 1897:
"I inclose an extract from the will of Alfred Nobel, dated Paris, November 27, 1895, and which, after disposing of about 2,000,000 kronor in legacies to relatives, servants, etc., directs that the remainder be devoted to the objects set forth in the extract given below. The amount thus devoted to the advancement of science and literature is estimated to be between 30,000,000 and 35,000,000 kronor, and it is thought that it will yield 3 per cent, per annum income, or from $240,000 to $270,000, to be annually distributed in five prizes. Each individual prize will therefore be worth between $48,000 and $55,000.
"Messrs. Ragnar Sohlman, of Bofors, Sweden, and Rudolf Liljequist, of Stockholm, Sweden, who now resides at Bengtsfors, Uddevalla, are named executors. I have written to them for information.
"I understand that several of the heirs at law of Mr. Nobel are contesting the will, and that it may possibly be years before the executors will be able to distribute the prizes."
The extract is as follows:
"My total remaining fortune, when capitalized, shall be disposed of in the following way: When the capital has been converted into good securities by the trustees, it shall form a fund, the interest of which shall be distributed annually as prizes to those persons who shall have rendered humanity the best services during the past year. The interest shall be divided into five equal portions, which shall be distributed as follows: One-fifth to the person having made the most important discovery or invention in the science of physics, one-fifth to the person who has made the most eminent discovery or improvement in chemistry, one-fifth to the one having made the most important discovery with regard to physiology or medicine, one-fifth to the person who has produced the most distinguished idealistic work of literature, and one-fifth to the person who has worked the most or best for advancing the fraternization of all nations and for abolishing or diminishing the standing armies as well as for the forming or propagation of committees of peace. The prizes for physics and chemistry shall be awarded by the Royal Swedish Academy of Science; that given to works of physiology and medicine by the Carolinska Institute at Stockholm; the prize for literature by the Royal Swedish Academy at Stockholm; and the prize given to the propagators of peace by a committee composed of five members who shall be selected by the Norwegian Storthing. It is my absolute wish that no importance shall be attached to any difference of nationality in awarding the prizes, which, consequently, shall be given to the most competent person, whether Scandinavian or not."
A rather vigorous criticism of the provisions of this will is to be found in The Spectator, p. 47, January 9, 1897.
Bruno Thieme, of Sieburg, Germany, has been granted U. S. Patent No. 541,899, of July 2, 1895, for a "Process of making Nitropentaerythrit " for use as an explosive. The claims cover a method of producing a compound for use as an ingredient in explosives, termed nitropentaerythrit, by treatment of pentaerythrit (produced by the condensation of acetaldehyde and formaldehyde in the presence of lime) with concentrated nitric and sulphuric acids.
The synthetic method for preparing pentaerythrit is given in Annalen 265, 316.
Pentaerythrit naturally suggests the body known as erythrite (also erythrol, erythro-glucin, phycite and butane tetrol), which is regarded as a tetracid alcohol, having the formula C4H4(OH)6. Erythrol occurs free in the Protococcus vulgaris, and is found combined with orsellinic acid, as erythrin, in many of the lichens and algae. Erythrol may be obtained from erythrin by saponification with sodium hydroxide or milk of lime. It is readily soluble in water, difficultly soluble in alcohol, and insoluble in ether. Erythrol possesses a sweet taste, and crystallizes from water in large quadratic crystals. When dissolved in fuming nitric acid nitroerythrit, or better, erythryl nitrate, crystallizes in brilliant plates which burn with a bright flame and explode like nitroglycerine when struck.
On the further study of "Nitrogen Chloride," W. Hentschel (Ber. Berl. Chem. Ges. 30, 1434-1437; 1897) finds that it is soluble in benzene, chloroform, carbon disulphide and ether; that the substance may be preserved in the solutions for some time in the dark, but that it decomposes rapidly on exposure to a bright light, and that the solvents present so diminish the sensitiveness of the nitrogen chloride that, for instance, a 10 per cent. Benzene solution can be ignited or poured upon a red-hot plate without a serious explosion resulting. The solutions are sulphur yellow, strongly refracting liquids. The solution in benzene is easily obtained by adding ammonium chloride to a 5 per cent. solution of sodium hydroxide which has been treated with chlorine, and agitating the mixture with benzene. About seven eighths of the active chlorine of the aqueous solution is converted into nitrogen chloride and there is obtained a clear, strongly refractive sulphur-yellow liquid possessing the repulsive odor characteristic of nitrogen chlorides.
The benzene solution, on decomposition by sunlight, gives nitrogen and benzene hexachloride; the carbon disulphide solution gives sulphur chloride; the carbon tetra-chloride gives nitrogen and chlorine; while the chloroform and ether solutions yield ammonia in place of nitrogen, ammonium chloride separating out and hydrogen chloride and chlorine being evolved. The chloroform also yields a trace of hexachlormethane, and the ether a liquid which boils at 800 to 1500 and which contains chlorine and reduces silver chloride.
In a paper on "The Naval Weakness of Great Britain," by Sir Charles W. Die, Cassier's Mag. 12, 425-440; 1897, after speaking of the necessity of a more complete preparation for war, he says: "In addition to the deficiency in those battleships, the numbers of which are vital to us, there are, as I have said, some points of doubt which are disagreeable to contemplate. The French carry high explosive shells in all their ships, and they count upon the rapid destruction of the unarmored and of the lightly armored portions of our battleships by means of these shells in an engagement, and believe that the poisonous fumes which the shells emit would render large portions of our armament unusable.
"Our own sailors think high explosive shells unsafe, and the fifty H. E. shells per ship that are now carried by our Channel squadron (and there are none, I believe, carried by any of our other ships) seem to have been taken on board to satisfy public Opinion. I am told that the fuses are at the wrong end, so that they are useless for armor piercing, because we have found that we cannot safely use them with the fuses at the right end. The French say that they can so make use of theirs.
"We do not appear to be in possession of shells of the same construction as the French shells, which are carried in the tropics in refrigerating chambers. Our officers generally think our own H. E. shells both useless and dangerous, and probably in time of war would drop them overboard. This is not the case with the French, and, therefore, presumably the French have a safer and better pattern of melinite shell than that which we have been able to supply; and it must be remembered that the French communicate to the Russians the whole of their inventions, and even manufacture, when necessary, for the Russian government.
"French authorities state that melinite is safer than picric acid, and this, which is the basis of a common yellow pigment, is carried everywhere. In the report on the French naval budget for 1897 it is admitted that the French navy and the French army hold different views as to the power of piercing thin steel armor with H. E. shell.
"The navy contend that they can at least explode thin shells within the plate, thus making a big hole, and that all behind will soon lie open and be swept by a fire in the explosions of which no man can breathe."
Through the courtesy of H. M. Inspectors of Explosives, we have been enabled to secure a copy of the second edition of "A Dictionary of Explosives," by the late Lieut-Col. J. P. Cundill, R. A., which is entirely rearranged and brought up to December, 1894, by Capt. J. H. Thomson, R. A. A comparison with the first edition shows that the topics are now arranged in alphabetical order, instead of the inconvenient subdivision into classes of the former edition; that the introductory matter has been increased from 15 up to 44 pages, and the dictionary proper from 108 up to 183 pages, it having at the end a valuable "Index to Ingredients" of explosives. Owing to the misuse which has been made of the former edition, this book can now only be purchased by permit of the Home Office.
The Smokeless Powder Company, Limited, has issued for circulation the lectures delivered by L. G. Duff Grant at the Museum of Practical Geology, October 28 and November 4, 1896, under the title "Smokeless Powder: its appliances, practice and purpose." The lectures are issued in two parts, the first being devoted to a general survey of explosives and smokeless powders, the second to a description of the works of the company and the results obtained with their product. This second part is quite extensively illustrated. It would appear from the statements on pages 12-14 of Part I that the position of cordite is not yet assured.
"Nitro-Explosives," by P. Gerald Sanford, is announced as a practical treatise on the properties, manufacture and analysis of nitrated substances, including the fulminates, smokeless powder and celluloid. The book shows that a considerable amount of material has been collected, but the not infrequent " slips " show that he is not practically familiar with the arts about which he writes, while errors in proper names, which are by no means infrequent, show that he has been careless in reading or transcribing. The errors are so frequent as to mislead any but those who are thoroughly conversant with the subjects treated of.
Through the courtesy of Professor Louis Amateis, we are in receipt of "Ascanio Sobrero. Notizie Biografiche," by Professor Vincenzo Fino. This appears as a reprint from Vol. 31 of the Annals of the Academy of Agriculture of Turin. There is appended a list of the published writings, numbering 123 titles, from which it appears that, in addition to his notable discovery of nitroglycerine and his researches on other explosive nitrates, he gave much attention to mineral analysis, collaborated in research with Avogadro and other eminent chemists, and published a manual on chemistry as applied to the arts, in four volumes. He was born October 12, 1812.
J. B. Bailliere et Fils, Paris, announce "Les explosifs et les explosions" au point de vue medico-legal by P. Brouardel, Dean of the Faculty of Medicine of Paris, and "Dynamite et dynamiteurs," Les engines anarchistes, 1894, no author being given.
The eminent bibliographer, Dr. H. Carrington Bolton, has just called our attention to a "Bibliographical Index to the Russian and Foreign Literature of Explosives from 1529 to 1882," by A. Heckel. We are able to quote the title only, as the work itself is not accessible to us. It is a curious coincidence that this work should have appeared simultaneously with the annotator's "Index to the Literature of Explosives," and it is to be noted that neither of them is recorded in Guttmann's Bibliography appended to his "Manufacture of Explosives," published in 1895.
Arms and Explosives 5, 74; 1897, contains an extended review of "A Bibliography of Guns and Shooting," by "Wirt Gerrare," in which the work is spoken of in the most approving terms. The main body of the work appears to have been brought up to July, 1894, and an appendix added to bring it up to the end of 1895. The author's name is William Oliver Greener. It is odd that the reviewer should have omitted to give the date of publication, which is presumably 1896 or 1897.
The Neues vom Bfichermarkte of the Mitt. gegen. Artill. Genie-Wesens, page 439, 1896, simply notes " Das Dynamit und seine cultur-historische und technische Bedeutung," by Nobel.
"A Hand-book of Modern Explosives," by M. Eissler, is the second edition of a now well-known book first published in 1890. This new edition is enlarged by about one hundred pages and fifty illustrations. The principal additions treat of the testing of the materials for the manufacture of nitroglycerine, the recovery of the spent acids, and the properties of frozen nitroglycerine explosives, while an entire new chapter is devoted to nitrogelatine and gelatine dynamite in their practical applications. It is unfortunate that the book should be marred by errors, and especially that the formulas given for calculating the results of analysis in the tests of acids should be wrong.