[ 145 ] 



XX. Proceedings of Learned Societies. 



ROYAL SOCIETY. 



[Continued from p. 78.] 

 April 19. — Lieut. -General Sabine, President, in the Chair. 

 rPHE following communication was read : — 



-*• "Researches on Gun-cotton. — Memoir I. Manufacture and 

 Composition of Gun-cotton." By F. A. Abel, F.R.S., V.P.C.S. 



A review of the researches on the production, properties, and com- 

 position of gun-cotton hitherto published, and a brief examination 

 into the probable causes of the discrepancies exhibited between the 

 results and conclusions of different experimenters, are followed in 

 this paper by a criticism of the several steps in the system of manu- 

 facture of gun-cotton, as prescribed by Baron v. Lenk. 



The conclusions arrived at on this subject are founded upon care- 

 fully conducted laboratory- experiments, and upon extensive manu- 

 facturing operations carried on during the last three years at the 

 Royal Gunpowder Works, Waltham Abbey. In some of these ope- 

 rations v. Lenk's system of manufacture, as originally communi- 

 cated to the English Government by that of Austria, was strictly 

 followed ; in others, various modifications were introduced in differ- 

 ent stages of the manufacture — such as in the composition of the 

 acids used, in the proportion borne by the cotton to the acids in 

 which it remained immersed, in the duration of the treatment of 

 cotton with the acids, and in the methods of purification to which 

 the gun-cotton was submitted. 



Exception is taken to one or two points in the general system of 

 manufacture, and directions are indicated in which they may be ad- 

 vantageously modified ; but the general conclusion arrived at is that, 

 although Baron v. Lenk cannot be said to have initiated any new 

 principle as applied to the production of gun-cotton, he has suc- 

 ceeded in so greatly perfecting the process of converting cotton into 

 the most explosive form of pyroxyline or gun-cotton, and also the 

 methods of purification, as to render a simple attention to his clear 

 and definite regulations alone necessary to ensure the manufacture 

 of very uniform products, which are unquestionably much more 

 perfect in their nature than those obtained in the earlier days of the 

 history of gun-cotton. Great stress is laid upon the fact that de- 

 viations from the prescribed process which at first sight may appear 

 trivial (such as a slight modification in the strength of the acids 

 used, the neglect of proper cooling-arrangements) are certain to 

 lead to variations in the products of manufacture, affecting their 

 explosive characters, or their permanence, or both. A considerable 

 deviation from the normal composition, due evidently to some 

 accidental irregularities in the course of manufacture pursued, has 

 been exhibited occasionally by gun-cotton obtained from the manu- 

 factories at Hirtenberg and Stowmarket. 



The composition of gun-cotton has been made the subject of a 

 very extensive series of experiments, both analytical and synthetical. 

 The material employed in the analytical researches consisted of ordi- 

 nary products of manufacture, prepared at Waltham Abbey, and 



Phil. Mag. S. 4. Vol. 3.2. No. 214. August 1866. L 



