Chemical powder

“ Unless the crystals of the nitrate of copper are moistened, no heat will be produced.
Fiery Powder.
Put three ounces of rock alum and one ounce of honey or sugar into a new earthen dish, glazed, and which is capable of standing a strong heat; keep the mixture over the fire, stirring it continually until it becomes very dry and hard; then remove it from the fire and pound it to a coarse powder. Put this powder into a long-necked bottle, leaving a part of the vessel empty ”

“ A powder of similar composition is produced by the action of powerful chemical reagents on sugar, lignin, &c. When acted upon by dilute boiling solution of caustic potassa, this substance yields a deep-brown solution, from which acids precipitate a flocculent brown substance generally called ‘ulmic’ or ‘humic acid.’ Both bodies require further investigation, as they are supposed to vary exceedingly in composition. ”

“ Bleaching powder is easily acted upon by the carbonic acid in the air, which liberates the weak hypochlorous acid. This, of course, results in a loss of available chlorine. The original material for analysis should be kept in a closed container and protected form the air as far as possible. It is difficult to obtain analytical samples which are accurately representative of a large quantity of the bleaching powder. The procedure, as outlined, will yield results which are sufficiently exact for technical purposes. ”

“ The explosive compound manufactured according to this invention differs essentially from the above mentioned powder, in that its progressive quality is obtained, in the latter case, in a purely mechanical way, by altering the size of the saltpetre crystals, while in the former case it is obtained in a chemical way, by introducing chemical substances in the outer layers of the compound, capable of modifying its explosive character. ”

“ In the chemical examination of gunpowder the points to be ascertained are, in addition to moisture, freedom from chlorides or sulphates, and correct proportion of nitre and sulphur to charcoal.
Products of Fired Powder and Changes taking place on Explosion.—With a mixture of the complexity of gunpowder it is quite impossible to say beforehand what will be the relative amounts of products. The desired products are nitrogen and carbon dioxide as gases, and potassium sulphate and carbonate as solids. ”

“ In smokeless powder the oxygen is held in chemical union with nitrogen and hydrogen, but the bond between the nitrogen and the other elements is weak, so that when ignited the other more active elements are enabled easily to unite at the expense of the nitrogen. ”

“ However, powder is usually effective only on objects which have a hard, smooth, nonabsorbent surface, such as glass, tile, and various types of highly polished metals and is usually not effective on absorbent materials, such as paper or unfinished wood or metal, which absorb perspiration so that there is nothing on the material’s surface to which the powder can adhere. ”

“ All powder, whether it is intended for blasting, hunting, rifle-shooting, or warfare purposes, is made in the same general way, and so, in telling of a visit I recently made to the Du Pont Works, near Wilmington, I shall reveal no secrets if I describe the various mills and processes which practically all powder goes through before it is finished. Ordinary powder is composed of three ingredients—saltpetre, sulphur, and charcoal, or nitrate of soda, sulphur, and charcoal. Powder intended for blasting is generally made with soda; powder intended for shooting is generally made with saltpetre. ”

“ THE POWDER STILL WORSE
So much for the liquid. The powder seems to be something entirely different, for, according to the chemist’s report, over 90 per cent. of it is inert, absorbent, talcum-like material. There is enough camphor and carbolic acid to give the powder an odor and thus mislead physicians, especially those who are in the habit of taking for granted that whatever statements nostrum manufacturers make are true. ”

“ As charcoal enters into the composition of gunpowder, and the effective force of powder depends considerably on the quality, as well as the proportion of charcoal, it is obvious for this purpose, it should be as pure as possible.
Carbon is always obtained from some of its combinations, as from pitch, tar, rosin, wood, and oil. Various processes are employed for this purpose. Thus, by the combustion of rosin and oil, as well as pitch, tar, turpentine, &c. a soot is [90] formed that collects, called lampblack, which is nothing more than the carbon or charcoal. ”

“ When the powder is newly made, or 'green,' the solvent is given off rapidly; but as the percentage of the solvent in the mass is reduced, it volatilizes less rapidly and comes off less freely. When the solvent is reduced to about 10 per cent., this closed-circuit process is discontinued and the drying of the powder is completed in the ordinary drying houses. ”

“ On the small scale, pulverisation is usually performed by means of a pestle and mortar; on the large scale, by stamping, grinding or cutting the substance in a mill. A few soft substances, as carbonate of magnesia, carbonate of lead, &c., may be pulverised by simply rubbing them through a fine sieve, placed over a sheet of paper; whilst many hard, gritty substances can only be reduced to fine powder by porphyrisation or levigation. Elutriation, or ‘washing over,’ is adopted for several substances, as chalk, antimony, &c., which are required to be reduced to fine powder on the large scale. ”

“ Up to a certain pressure, hardness, density, and size of grain of a powder have an effect on the rate of burning and therefore on pressure. Glazing or polishing powder grains, also exerts a slight retarding action on burning and enables the powders to resist atmospheric moisture better. Excess of moisture in gunpowder has a marked effect in reducing the explosiveness. All powders are liable to absorb moisture, the quality and kind of charcoal being the main determinant in this respect; hard burnt black charcoal is least absorbent. ”

“ On progressively trying solutions of weaker and weaker preservative power, it will be remarked, that the quantity of the detached powder, and the proportion of carbonate in it, progressively increase; and likewise, that what is formed on the lead adheres more and more loosely. In distilled water and weak solutions of acetate of soda, or nitrate of potass, the lead never becomes so firmly encrusted, but that gentle agitation of the water will shake off the powder. ”

“ Attempts have been made to impart a progressive combustion to ordinary black powder, by using in the outer layers of the same, saltpetre crystals of larger size than in the inner layer, but in this way the desired result will not be obtained, owing to the fact that the larger crystals make the product more porous, and as the quickness of combustion of powder increases with the porosity of the same, it will easily happen that a result is obtained which is contrary to the one sought for. ”

“ Care must be taken that all the dry ingredients be finely pulverised, and that the harder and gritty ones be reduced to the state of an impalpable powder, either by levigation or elutriation. The mixture of the ingredients must also be complete. This is the most readily effected by stirring them well together until they form an apparently homogeneous powder, and then passing this powder through a very fine sieve. Those which contain volatile substances should be preserved in closely corked wide-mouth bottles, and those which contain acidulous or gritty matter should not be frequently employed. ”

“ The vessel is then removed from the fire, and phosphorus, 11⁄2 to 2 parts, is gradually added, the mixture being agitated briskly and continually with a ‘stirrer’ having wooden pegs or bristles projecting at its lower end. When a uniform emulsion is obtained, chlorate of potassa, 4 to 5 parts, powdered1035 glass, 3 to 4 parts, and red lead, smalt, or other colouring matter, a sufficient quantity (all in a state of very fine powder) are added, one at a time, to prevent accidents, and the stirring continued until the mixture is comparatively cool. ”

“ If the acidity does not fall within these limits it must be corrected by soaking the powder before chroming for twenty minutes in ten to twelve times its weight of water, to which the requisite calculated quantity of standard alkali or acid has been added. The hide powder must not swell in chroming to such an extent as to render difficult the necessary squeezing to 70-75 per cent. of water, and must be sufficiently free from soluble organic matter to render it possible in the ordinary washing to reduce the total solubles in a blank experiment with distilled water below 0.005 gm per 100 c.c. ”

“ There is a considerable difference in the proportions used by different nations; but, from the many accurate and conclusive experiments of the French chemists, their formula is certainly the most perfect. In English powder, three-quarters of the composition are nitre, and the other quarter is made up of equal parts of charcoal and sulphur; but sometimes, to seventy-five parts of nitre, fifteen of charcoal is used, adding ten of sulphur. Their government powder is the same for cannon, as for small-arms. ”

“ The blow-pipe is especially useful, though to the skilled assayer often unnecessary. The ore is first powdered, and any metallic flakes picked out and tested separately. A fair sample must be selected, otherwise all the work will be thrown away and the result be valueless.
The next step is weighing the ore and the reagents. Moisture is drawn off by heating in a crucible, a low heat being sufficient. Roasting will eliminate sulphur, antimony, arsenic, etc., and must take place in a flat dish, so that the air may have free access. The powder should be stirred frequently. ”

“ Some of the sulphur is lost, part combining with the metal of the apparatus and part with hydrogen in the charcoal. The military powders of most nations can be represented by the formula 16KNO3 + 21.2C + 6.6S, proportions which are reasonably near to a theoretical mixture, that is one giving most complete combustion, greatest gas volume and temperature. The combustion of powder consists of two processes: (i.) oxidation, during which potassium carbonate and sulphate, carbon dioxide and nitrogen are mainly formed, and (ii.) ”

“ The products of combustion of smokeless powder are not only practically all gaseous, but also they are much hotter than the products of combustion of the old, smoky, black powder. Owing to this fact, smokeless powder may be considered about four times as powerful as the old black powder. ”

“ Let cool, grind the turbid mass obtained, and pour a little coal benzine or petroleum benzine over it in a flask. By repeated shaking of the flask the soluble portion of the molten mass is dissolved; filter after allowing to settle; into the filtrate put 300 to 400 parts of bronze powder of any desired shade, the brocades being especially well adapted for this purpose. If the metallic powder remains distributed over the mass for a long time it is of the right consistency; if it deposits quickly it is too thin and a part of the solvent must be evaporated before stirring in the bronze powder. ”

“ It is most certain, that, if powder be kept long in a damp place, it will become weak and moist, and great part of it will be formed into hard lumps, which is a certain sign of its being damaged. When powder is thus found, you will also see at the bottom of the barrel some saltpetre, which, by being wet, will separate from the sulphur and coal, and always 17 fall to the bottom of the vessel wherein the powder is contained, and settle there in the form of a white downey matter ”

“ It has also been ascertained that the greater the pressure, the higher is the proportion of carbonic acid produced, so that the more work the powder has to do, the more perfect will be the combustion, and, consequently, the greater will be the force developed. ”

“ This powder is extracted with petroleum spirit, and the solution shaken with water containing a trace of copper acetate. If rosin be present, the petroleum spirit will be coloured emerald-green.
Borax, soda crystals, and ammonia are all used to dissolve shellac, and it may be asked: Which of these is least injurious to wool? and why? How is their action modified by the presence of dilute sulphuric acid in the wool? I would say that soda crystals and ammonia are alkalis, and if used strong, are sure to do a certain amount of injury to the fibre of wool, and more if used hot than cold. ”

“ Other advantages suggest themselves in the use of Gunpowder, such as the comparative cheapness of the ingredients composing it, and the ease with which they may be obtained; for the sulphur and saltpetre are very abundant productions of nature, and the charcoal can be manufactured cheaply and with great facility, and if care is taken in the process of the fabrication of powder, little deterioration will take place on its exposure to heat or moisture. ”

“ The present German powder is made from such a compound of tri-nitro-cellulose and soluble nitro-cellulose.
Nevertheless, this compound is a makeshift as compared with the nitro-cellulose used by this Government. Ours is a far better explosive, and is less erosive on the guns, because the gases which it generates are not so hot. We have the best smokeless powder in the world, and, after this war is over, our powder will be universally used. ”

“ The excellent preservative qualities of English and American powders are largely due to their high densities,—the standard being about 1.75. A certain degree of density is absolutely essential to grain powder to prevent the inflamed gases from penetrating the pores of the powder and flashing off the whole mass to the destruction of the gun. In the manufacture of powder the density depends, first, upon the amount of trituration to which the ingredients are subjected in the incorporating mill ”