Chemical History of Gun-Cotton and Xyloidine. 527 



Under this supposition the increase in weight in the pre- 

 paration would be 4r66 per cent. ; very similar to that cal- 

 culated from the results obtained by the action of nitric acid, 

 sp. gr. 1'45, on pyroxyline, namely, 3905 and 4ri per cent. 



In order to add an additional proof of the identity of the 

 two substances obtained by the action of nitric acid of sp. gr. 

 1*45 on cotton and on pyroxyline, and also of the fact that 

 pyroxyline is reproduced by the action of mixed sulphuric 

 and nitric acids upon the new product, the experiment was re- 

 peated with a portion of the substance made from pure cotton : 

 the result was pyroxyline. In the transformation 26*56 grs. 

 became 38'04 : now these 26*56 grs. were produced from 

 21*81 grs. of the original cotton ; hence the increase upon the 

 cotton itself would be 16*23 grs., or 74*4 per cent., coinciding 

 with the amount usually obtained in the preparation of pyr- 

 oxyline. 



I. From these results it appears that in the treatment of 

 woody fibre by nitric acid raised to its highest degree of 

 strength by the addition of sulphuric acid, 5 equivalents of 

 the acid combine with 1 of lignine to produce pyroxyline, 

 displacing 5 equivalents of the elements of water, as indicated 



by the formula C24S c-vf/^ fOao* The amount per cent, of 



carbon and hydrogen hence deduced closely agrees also with 

 that assigned by Mr. Ransome * and M. Pettenkofer f. 



Calculated. Ransome. Pettenkofer. 

 Carbon . . 26*23 26*28 26*26 



Hydrogen . 2*73 3*16 2*75 



In this case the synthetical experiment would give an in- 

 crease of 69*44 per cent. — nearly the amount obtained in the 

 best experiments. My own analyses however have yielded a 

 somewhat larger amount of carbon. 



II. If lignine be treated with nitric acid combined with 

 more than 1 equivalent of water, another compound is pro- 

 duced, containing a smaller proportion of the elements of 



nitric acid, most probably C34 < „ ^q > 0<^^ and very closely 



resembling, but not identical with, pyroxyline. 



C24H,oO^ + 3(NO„2HO) = C^|f^7^Jo,o + 9HO. 



Also if pyroxyline itself be treated with nitric acid con- 

 taining 3 equivalents of water, the same compound results : 



* Phil. Mag., January ] 847. 



\ Pharmaceutisches Central BlattfTiec.ZOi^lS'lQ, 



