272 ME. ABEL'S EESEARCHES ON GUN-COTTON. 



evidence of the possibility of producing four distinct varieties of pyroxylin, by sub- 

 mitting cotton-wool to the action of different mixtures of nitric and sulphuric acids. 

 Moreover, by carefully determining the increase of weight sustained by the cotton upon 

 immersion in acid mixtures of different composition, and also by applying a new process 

 to the examination of the products, Hadqw succeeded in establishing the composition of 

 three of these* substances. 



By repeated immersion of pure cotton in a mixture of the strongest sulphuric and 

 nitric acids, HaDOW obtained an increase of 81-^34 per cent., a number considerably 

 (higher than that' obtained by previous experimenters, and nearly corresponding to 

 ithe t;heoretical gain (83-3 per cent.) which cotton would sustain by its conversion 

 into -.a product of th.^ formula 



^is^2i^.i^ 9N02, or Ggjg^^ 1 05, or Ci^Hu©;, S^,0,(C,,TI,,0,„ mO„ Hadow). 



By dete^miniDg, in the a'orm of nitric acid, the oxide of nitrogen contained in the pro- 

 duct, and reproducing the cotton from the latter by the action of potassic sulphhydrate, 

 Hadow moreover obtained numerical results closely agreeing with those which should 

 be furnished iby itrinitro-cel lulose or trinitric cellulose, and therefore confirmatory of 

 the conclusion which was basv °d upon the weight of the product furnished by as com- 

 plete a treatment .as possible c ^f the cellulose with the strongest nitric and sulphuric 

 acids. Similarly, Mabow established the composition of two lower mitric-products, 

 paving respectively ijtite formulae 



G,8 n^ 0,5,- 8N 02 (C3e H,, O^, 8N O4) 

 and 



«,8 H2,-0,5, '.'N O, (C36 H33 O30, 7N OJ, 



and differing ham .the 'JaigJiest compo und in being soluble in njixtures of ether and 

 alcohol. 



Not long after Ha®®w's researches were made known, Bechamp published a con- 

 tinuation of his .experioients with soluble gun-cotton. In this paper he adheres to the 

 concinsion that Eblouze's formula for pyro.xylin (C24H17O17, SNOj) is correct, because 

 he obtains, by the action, of ammonia and potassa upon that substance, products the 

 composition of which he represents by the foimulse 



C24H17O,;, 4NO5 and C24H,7 0i;, 3NO5. 



KedtenbachJib, Scilrottek, and Schneider, in a joint report prepared by them in 

 1863 on gun-cotton manufactured by Baron von Lenk, adopted the view that the most 

 explosive variety of gun-cotton was trinitro-cellulose, and quoted several satisfactory 

 analytical results in pr<oof of their assertion that gun-cotton prepared according to 

 Lenk's directions was that substance in a nearly pure condition. 



The composition of the most explosive gun-cotton was indeed veiy generally regarded 

 as definitely established to be trinitro-cellulose, or trinitric cellulose, until the publica- 



