iS73-] Recent Changes in British Artillery Materiel. 333 



results are so important, and their realisation will acquire 

 so high a value as bearing upon the employment of gun- 

 cotton for military purposes, that they think the subject 

 should be at once fully taken up. 



Recommend that Mr. Abel be authorised to proceed with 

 his experiments, and to prepare for trial samples of the 

 mixed substances as above described. 



The principal points which the committee think deserving 

 of investigation are : — 



1. Whether, when saltpetre is incorporated with gun- 



cotton pulp, the mixture can be compressed into discs 

 which possess advantages over discs of pure gun-cotton 

 in being harder, less liable to flake, less inflammable, more 

 stable, and not less efficient. 



2. The exact proportion of saltpetre which must be incor- 



porated with gun-cotton pulp to develope the same 

 amount of explosive force as pure gun-cotton, weight 

 for weight. 



3. An investigation into this and other properties of gun- 



cotton incorporated with nitrate of soda and chlorate 

 of potash. 



4. The cost of each of these modifications of gun-cotton, 



compared with ordinary gun-cotton; and their relative 

 rate of production. 



5. The special military uses for which each of them seems 



particularly suitable. 



An important improvement in the manufacture of gun- 

 cotton has been suggested by Mr. Abel, and the expectations 

 he had formed have since been fully confirmed. The 

 improvement consists in the addition of a proportion of 

 ammonia to the gun-cotton at, or soon after, the com- 

 mencement of the washing process ; the effect of which is, 

 not only to neutralise any free acid that may be left in the 

 beaten-up pulp, but to act as a powerful solvent in removing 

 the resinous and other organic matters locked up in the 

 fibres of the cotton, the presence of which materially inter- 

 feres with the stability of the finished product. 



The importance of this step in manufacture may be judged 

 of by the fact that, whereas the poaching or washing ope- 

 ration has hitherto required the use of warm water, and has 

 had to be continued for a period of sixty hours as a minimum, 

 but extending sometimes to ten or even fourteen days before 

 complete removal of these substances and consequent puri- 

 fication is obtained, the ammoniacal washing completes the 

 operation with cold water in about twenty-four hours. 



This new development effected in the manufacture of 



vol. in. (n.s.) 2 x 



