98 Report vS.A.A. Advanxement of Science. 



cellulose is alwavs the l)esl, other thini^s being satisfactory. We 

 shall, therefore, start by assuming that \ve have an excellent nitro- 

 cellulose, the test of its excellence being its capacity to convert nitro- 

 glycerine into a doughy mass with the minimum quantity. The 

 manufacture of this nitro-cellulose is a most ticklish matter, the 

 ultimate quality depending on so man\ different things, among 

 Avhich I ma\' cite the source of the raw cotton, the extent to which 

 it has been washed or bleached, i.e., converted into oxycellulose, or 

 other quasi-cellulose. the strength of the acids, the temperature <jf 

 nitration, the method of washing, and a host of other details. How- 

 ever, it is possible to ])roduce a good nitro-cellulose which is entirely 

 soluble in nitroglycerine. Other nitro-celluloses higher in the scale 

 of nitration, such as gun cotton, are almost completely insoluble in 

 nitro-glvcerine. and some of them much lower are equally insoluble. 

 When nitrocellulose in the shape of pulji is mixed with nitro-glycerine- 

 in the heat, it dissolves ver\ rapidh. and if the jjrocess of solution 

 be tiuther continued in a mai'hine something like a i)read-kneading 

 machine, what we call ihe maximum gelatinising effect is jiroduced. 

 and ihe rrsull is a plasti*- dough which has onlv to be jjressed through 

 a sausage machine in order to make cartridges. It does not 

 take much imagination to understand how different sizes of nozzles 

 or dies will ])roduce different diameters of cartridges, and this is 

 reall\ how the different sizes are produced. A good Blasting 

 Gelatine ought not to contain more than 8"J5",, niiro-celiulose, and 

 as will be seen from the dummy specimen exhibited, it is a pliable,. 

 rubber\ mass, having generally a yellowish milk\ while appearance. 

 The milkiness comes from small globules of air imprisoned ihrough- 

 f)ut the mass, but after a few months' storage thesi' disajipear. and the 

 Ijody l)ecomes amber-coloured and quite transparent. 



Thi.s plasticity makes Blasting Gelatine one of the safest ex- 

 plosives to handle, and if statistics be carefully examined, ihev will 

 reveal the fact that in the hands of the experienced peo})le who 

 manufacttire it. an accident is a very rare occurrence. i''or this 

 same reason it is calculatecl that the initial shock necessar} to ex- 

 ])lode Blasting Gelatine is six times as great as that for Dvnamite. 

 Blasting (jelatine is. therefore, comparatively insensiti\e to e\])losion 

 by influence, and some years ago. when the ambition of every 

 artillerist was to throw the biggest projectile the longest distance 

 with the greatest effect, the now. forgotten Zulinskv Gun, the inven- 

 tion ot a very clever American, made its ai)pearan(e. It did do all. 

 or nearl\ all. that its inventor claimed for it. and threw- a large pro- 

 jectile with an equally large charge of Blasting Gelatine very long 

 distances, but for reasons which we need not discuss the idea has 

 now been fmally abandoned. Another excellent property of Blast- 

 ing Gelatine is the fact that i( suffers practically no deterioration 

 from contact with water. In fact, it can be u.sed in wet and dry 

 holes with eqtial facilitx. and it can l)e stored under water for an 

 indefinite period. 



The theoretical pressure developed on explosion is much the 

 same as in nitro-glycerine. One might fairly expect it to be higher.. 



