Part 17 (1/2)

_Emmensite_ is the invention of Dr Stephen Emmens, of the United States

The E picric acid with furavity of 152 The acid dissolves with the evolution of red fumes The liquid, when cooled, deposits crystals, stated to be different to picric acid, and lustrous flakes These flakes, when heated in water, separate into t bodies One of these enters into solution and forms crystals unlike the first, while the other body remains undissolved The acid crystals are used mixed with a nitrate

Emmensite has been subjected to experiment by the direction of the US

Secretary for War, and found satisfactory A sample of Emmensite, in the form of a coarse powder, was first tried in a pistol, and proved superior in propelling power to ordinary gunpowder When tested against explosive gelatine, it did very good work in shattering iron plates It is clai the only high explosive whichThis view is supported by the trials made by the American War Office authorities, and shows E and as a smokeless powder Its explosive power, as tested, is 283 tons per square inch, and its specific gravity is 18

Abel proposed to use picric acid for filling shells His _Picric Powder_ consisted of 3 parts of saltpetre, and 2 of picrate of ammonia

_Victorite_ consists of chlorate of potash, picric acid, and olive oil, and with occasionally sorey powder, and leaves an oily stain on paper, and it is very sensitive to friction and percussion The composition is as follows:--KClO_{3} = 80 parts; picric acid, 110 parts; saltpetre, 10 parts; charcoal, 5 parts It is not land _Tschiner's Powder_ is very similar to Victorite in composition, but contains resin A list of the chief picric powders will be found in the late Colonel JP Cundill, RA's ”Dictionary of Explosives”

CHAPTER VII

_analYSIS OF EXPLOSIVES_

Kieselguhr Dynamite--Gelatine Compounds--Tonite--Cordite--Vaseline-- Acetone--Scheme for analysis of Explosives--Nitro-Cotton--Solubility Test-- Non-Nitrated Cotton--Alkalinity--Ash and Inorganic Matter--Detere, Champion and Pellet's, Schultze-Tieman, and Kjeldahl's Methods--Celluloid--Picric Acid and Picrates--Resinous and Tarry Matters-- Sulphuric Acid and Hydrochloric Acid and Oxalic Acid--Nitric Acid-- Inorganic Impurities--General Impurities and Adulterations--Potassium Picrate, &c--Picrates of the Alkaloids--analysis of Glycerine--Residue-- Silver Test--Nitration--Total Acid Equivalent--Neutrality--Free Fatty Acids--Combined Fatty Acids--Impurities--Oleic Acid--Sodium Chloride-- Determination of Glycerine--Waste Acids--Sodium Nitrate--Mercury Fulminate--Cap Composition--Table for Correction of Voluuhr Dynaenerally consists of 75 per cent of nitro-glycerine and 25 per cent of the infusorial earth kieselguhr The analysis is very sirms of the substance, and place over calciuht days, and then re-weigh The loss of weight gives the enerally be very small, probably never more than 1 per cent, and usually less

Mr James O Handy, in order to save ti rm of the material in a porcelain crucible 1 inch in diameter The crucible is then supported at the bottom of an extra wide-mouthed bottle of about 600 cc capacity Air, which has been dried by bubbling through strong sulphuric acid, is non over the surface of the sample for three hours by means of an ordinary aspirator

The air should pass approximately at the rate of 10 cc per second The tube by which the dry air enters the bottle extends to within 1 inch of the crucible containing the dynamite An empty safety bottle is connected with the inlet, and another with the outlet of the wide-ainst theover by the air current of sulphuric acid from the acid bottle into the sample, whilst the second prevents spas the salycerine

The dry substance hed, and the nitro-glycerine extracted in the Soxhlet apparatus with ether The ether should be distilled over at least twenty-four times

I have found, however, that much quicker, and quite as accurate, resultsthe dynamite in contact with ether in a s it overnight is better-- and decanting, and again allowing the substance to remain in contact with a little fresh ether for an hour, and finally filtering through a weighed filter, drying at 100 C, and weighing This gives the weight of the kieselguhr The nitro-glycerine must be obtained by difference, as it is quite useless to evaporate down the ethereal solution to obtain it, as it is itself volatile to a very considerable extent at the temperature of evaporation of the ether, and the result, therefore, will always be uhr can, of course, be examined, either qualitatively or quantitatively, for other mineral salts, such as carbonate of soda, &c An actual analysis of dynaave-- Moisture, 092 per cent; kieselguhr, 2615 per cent; and nitro- glycerine, 7293 per cent, the last being obtained by difference

~Nitro-Glycerine~--It is solycerine If an oily liquid is oozing from the substance, soak a drop of it in filter paper If it is nitro-glycerine it will reasy spot If the paper is now placed upon an iron anvil, and struck with an iron hahted it burns with a yellowish to greenish fla sound, and placed upon an iron plate and heated from beneath, it explodes sharply

If a few drops of nitro-glycerine are placed in a test tube, and shaken up with methyl-alcohol (previously tested with distilled water, to see that it produces no turbidity), and filtered, on the addition of distilled water, the solution will becolycerine will separate out, and finally collect at the bottolycerine in methyl-alcohol, a few drops of a solution, composed of 1 volume of aniline, and 40 volumes sulphuric acid (184) be added, a deep purple colour will be produced

This colour changes to green upon the addition of water If it is necessary to deterlycerine quantitatively in an explosive, the schee 213 may be followed Ether is the best solvent to use

Nitrogen should be determined in the nitrometer

~Gelatine Compounds~--The sielatine, as it consists of nothing but nitro-cotton and nitro- glycerine, the nitro-cellulose being dissolved in the glycerine to for about 92 per cent of nitro- glycerine to 8 per cent nitro-cotton, but the cotton is found as high as 10 per cent in soelatines, with varying proportions of wood-pulp and saltpetre (KNO_{3}) elatine The rms of the substance, previously cut up into small pieces with a platinum spatula, and place over calciuh The loss equals enerally very small Or Handy's method may be used The dried sample is then transferred to a small thistle-headed funnel which has been cut off frolass wool, and round the top rim of which a piece of fine platinum wire has been fastened, in order that it may afterwards be easily reht of this funnel and the glass wool must be accurately known It is then transferred to the Soxhlet tube and exhausted with ether, which dissolves out the nitro-glycerine The weighed residue must afterwards be treated in a flask with ether-alcohol to dissolve out the nitro-cotton

But the more expeditious elatine to a conical Erlenmeyer flask of about 500 cc

capacity, and add 250 cc of a mixture of ether-alcohol (2 ether to 1 alcohol), and allow to stand overnight Sometimes a further addition of ether-alcohol is necessary It is always better to add another 300 cc, and leave for twenty minutes or so after the solution has been filtered off The undissolved portion, which consists of wood-pulp, potassiuh a linen or paper filter, dried and weighed

~Solution~--The ether-alcohol solution contains the nitro-cotton and the nitro-glycerine in solution[A] To this solution add excess of chloroform (about 100 cc will be required), when the nitro-cellulose will be precipitated in a gelatinous forh a linen filter, and allowed to drain It is useless to atteenerally causes it to set solid The precipitated cotton should then be redissolved in ether-alcohol, and again precipitated with chloroform (20 cc of ether-alcohol should be used) This precaution is absolutely necessary, if the substance has been treated with ether- alcohol at first instead of ether only, otherwise the results will bevery considerable quantities of nitro-glycerine The precipitate is then allowed to drain as completely as possible, and finally allowed to dry in the air bath at 40 C, until it is easily detached from the linen filter by the aid of a spatula, and is then transferred to a weighed watch-glass, replaced in the oven, and dried at 40 C until constant in weight The weight found, calculated upon the 10 gre of nitro- cellulose

[Footnote A: If the substance has been treated with ether alone in the Soxhlet, the nitro-glycerine will of course be dissolved out first, and the ether-alcohol solution will only contain the nitro-cellulose]

~The Residue~ left after treating the gelatine with ether-alcohol is, in the case of blasting gelatine, very s but carbonate of soda It should be dried at 100 C and weighed, but in the case of either gelignite or gelatine dynamite this residue should be transferred to a beaker and boiled with distilled water, and the water decanted soht or ten times, and the residue finally transferred to a tarred filter and washed for some time with hot water

The residue left upon the filter is wood-pulp This is dried at 100 C

until constant, and weighed The solution and washi+ngs from the wood are evaporated down in a platinum dish, and dried at 100 C It will consist of the potassium nitrate, and any other mineral salts, such as carbonate of soda, which should always be tested for by adding a few drops of nitric acid and a little water to the residue, and again evaporating to dryness and re-weighing Froht the soda can be calculated, sodiu been formed Thus--

Na_{2}CO_{3} + 2HNO_{3} = 2NaNO_{3} + CO_{2} + H_{2}O