Part 22 (1/2)

~Ballistite~--In the case of ballistite the treatranulated condition it need not be cut up

~Guttmann's Heat Test~--This test was proposed by Mr Oscar Guttmann in a paper read before the Society of Chemical Industry (vol xvi, 1897), in the place of the potassium iodide starch paper used in the Abel test The filter paper used is wetted with a solution of diphenylamine[A] in sulphuric acid The solution is prepared as follows:--Take 0100 grm of diphenylaround stopper, add 50 cc of dilute sulphuric acid (10 cc of concentrated sulphuric acid to 40 cc of water), and put the flask in a water bath at between 50 and 55 C At this temperature the diphenylamine will melt, and at once dissolve in the sulphuric acid, when the flask should be taken out, well shaken, and allowed to cool After cooling, add 50 cc of Price's double distilled glycerine, shake well, and keep the solution in a dark place The test has to be applied in the folloay:--The explosives that have to be tested are finely subdivided, gun-cotton, nitro-glycerine, dynaelatine, &c, in the saulations Sround in a bell-shaped coffee rm of the explosive (from the second sieve in the case of shed off and put into a test tube as hitherto used Strips of ashed filter paper, 25 lass rod as usual A drop of the diphenylalass rod, and the upper corners of the filter paper are touched with it, so that when the two drops run together about a quarter of the filter paper is ain into the water bath, which has been heated to 70 C The heat test reaction should not show in a shorter tiin by the reenish yellow colour, and from this moment the paper should be carefully watched After one or twoline between the wet and dry part of the filter paper, and this is the point that should be taken

[Footnote A: Dr G Spica (_Rivista_, Aug 1897) proposes to use hydrochloride of meta-phenylenedia Gelatine, Gelatine Dynaelatine, &c, is to be cut froth of the cylinder to be equal to its dia cut flat The cylinder is to be placed on end on a flat surface without any wrapper, and secured by a pin passing vertically through its centre In this condition the cylinder is to be exposed for 144 consecutive hours (six days and nights) to a te such exposure the cylinder shall not diht, and the upper cut surface shall retain its flatness and the sharpness of its edge

~Exudation Test~--There shall be no separation froelatine dynamite of a substance of less consistency than the bulk of the ree, transport, or use, or when the material is subjected three ti, or when subjected to the liquefaction test before described

~Picric Acid~--The material shall contain not more than 03 part of ht of the material dried at 160 F It should not contain more than a minute trace of lead

One hundred parts of the dry material shall not contain more than 03 part of total (free and combined) sulphuric acid, of which notpoint should be between 248 and 253 F

~Ammonite, Bellite, Roburite, and Explosives of similar Composition~-- These are required to stand the saun-cotton, &c

~Chlorate Mixtures~--The material must not be too sensitive, andItliable to reduce the chlorate Chlorides calculated as potassium chloride must not exceed 025 per cent The material must contain no free acid, or substance liable to produce free acid Explosives of this class containing nitro-coulator~--The ulator to use in connection with the heat-test apparatus is the one invented by Prof

FJM Page, BSc[A] (Fig 49) It is not affected by variations of the barometric pressure, and is simple and easy to fit up It consists of a therlass bulb 5/8 inch dia The ste and 1/8 inch to 3/16 inch internal diameter One and a half inch frolass tube, 1 inch long, of the salass tube (A), about 7/16 inch external dia, is fitted at one end with a short, sound cork (C, Fig 50) Through the centre of this cork a hole is bored, so that the stem of the therlass tube is closed by a tightly fitting cork, preferably of indiarubber (I), which is pierced by a fine bradawl through the centre

Into the hole thus , and sh to fit loosely inside the stem of the thermometer

[Footnote A: _Chemical Soc Jour_, 1876, i 24]

The therh a small funnel until the level of the mercury (when the thermometer is at the desired telass tube A, closed at its upper extrelass tube B passes into the stem of the thermometer, is now filled by means of the perforated cork at its lower extreas supply tube is attached to the top of the tube A, the burner to the T, so that the gas passes in at the top, down the fine tube B, rises in the space between B and the inside wall of the steulator is set for any given te the cork C, and consequently the tubes A and B, which are firmly attached to it, up or down the steas at the desired temperature

[Illustration: FIG 49--PAGE'S REGULATOR]

[Illustration: FIG 50--PAGE'S GAS REGULATOR, SHOWING BYE-Pass AND CUT-OFF ARRANGEMENT]

As soon as the temperature falls, the as is thus turned on, and the teas In order to prevent the possible extinction of the flaas to the regulator is connected with the tube which brings the gas fro 2)

This tap forms an adjustable bye-pass, and thus a sulator be coas supplied through the bye-pass must always be less than that required to ulator, placed in a beaker of water on a tripod, willfour or five hours within 02 C, and an air bath during six weeks within 05 C

To su filled with as supply as in diagra open, and the tube B unclosed by the as to completely expel the air in the apparatus Push down the tube A so that the end of B is well under the surface of the mercury Turn off the tap of the bye-pass until the smallest bead of flame is visible Raise A and B, and allow the temperature to rise until the desired point is attained Then push the tubes A and B slowly down until the flaulator will then keep the temperature at that point

~Will's Test for Nitro-Cellulose~--The principle of Dr W Will's test[A]

ularity hich nitro- cellulose deco of the re their forent a sufficiently high te kept in a constantly changing atmosphere of carbon dioxide, heated to the saen which result are swept over red-hot copper, and are then reduced to nitrogen, and finally, the rates of evolution of nitrogen are measured and compared Dr Will considers that the best definition and test of a stable nitro-cellulose is that it should give off at a high teen in equal times For the purposes of manufacture, it is specially important that the material should be purified to its li produces no further change in its speed of decomposition measured in the manner described

[Footnote A: W Will, _Mitt a d Centrallstelle f Wissench Techn

Untersuchungen Nuo-Babelsberg Berlin_, 1902 [2], 5-24]

The sarms) is packed into the decoh, and heated by an oil bath to a constant tenited copper, where they are reduced, and the nitrogen retained in thetubes Care must be taken that the acid decomposition products do not condense in any portion of the apparatus The air in the whole apparatus is first displaced by a streaenerator, or gas-holder, and passing through scrubbers, and this streahout the whole of the experi absorbed at the end of the systeainst the danger of explosions, which occasionally occur, the deco alls colass

Dr Will's apparatus has been modified by Dr Robertson,[A] of the Royal Gunpowder Factory, Waltha 51

~CO_{2} Holders~--Although objection has been taken to the use of coed large and variable amount of air present, it has, nevertheless, been found possible to obtain this gas with as little as 002 per cent of air Frequent estimations of the air present in the CO_{2} of a cylinder show that even with the commercial article, after the bulk of the CO_{2} has been reas contains only a very sradual and perfectly regular ave 003 per cent of air by voluave 002 per cent The advantage of using CO_{2} from this source is obvious when coas of constant composition from a Kipps or Finkener apparatus A micrometer screw, in addition to thethe rate of flow A blank experiment should be made to ascertain the amount of air in the CO_{2} and the correction s afterwards