MODERN EXPLOSIVES 25 



are ballistite and filite, the former being in sheets, the latter 

 in threads. Originally camphor was introduced, but its 

 use has been abandoned, a small quantity of aniline taking 

 its place. 



Sir Frederick Abel and Professor Dewar patented in 

 1889 the use of trinitrocellulose and nitroglycerin, for al- 

 though, as is well known, this form of nitrocellulose is not 

 soluble in nitroglycerin, yet by dissolving the bodies in a 

 mutual solvent, perfect incorporation can be attained. 

 Acetone Is the solvent used in the preparation of " cordite," 

 and for all ammunition except blank charges a certain pro- 

 portion of vaseline is also added. The combustion of the 

 powder without vaseline gives products so free from solid 

 or liquid substances that excessive friction of the projectile 

 in the gun causes rapid wearing of the rifling, and it is 

 chiefly to overcome this that the vaseline is introduced, 

 for on explosion a thin film of solid matter is deposited in 

 the gun, and acts as a lubricant. 



The proportion of the ingredients are: 



Nitroglycerin 58 parts 



Guncotton 37 " 



Vaseline 5 " 



Guncotton to be used for cordite is prepared as pre- 

 viously described, but the alkali is omitted, and the mass 

 is not submitted to great pressure, to avoid making it so 

 dense that ready absorption of nitroglycerin would not 

 take place. The nitroglycerin is poured over the dried 

 guncotton and first well mixed by hand, afterward in a 

 kneading machine with the requisite quantity of acetone 

 for three and a half hours. A water jacket is provided, 

 since on mixing the temperature rises. The vaseline is 

 now added, and the kneading continued for a similar 

 period. The cordite paste is first subjected to a prelimin- 

 ary pressing, and is finally forced through a hole of the 

 proper size in a plate either by hand or by hydraulic pres- 

 sure. The smaller sizes are wound on drums, while the 



