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



would be necessary to assume that the cotton-wool operated upon was pure cellulose ; 

 that the operation of conversion was an absolutely perfect chemical process ; that there 

 were no possible sources of loss in the production of the material ; and that in all 

 laboratory operations which had furnished an increase of weight above the theoretical 

 demand (7 7' 8 per cent.), some substance, differing in composition from the ordinary 

 products of manufacture, must have been obtained. 



8. The identity in their characters, and close resemblance in composition, of the most 

 perfect products of laboratory operations and of the purified products of manufacture, 

 the very close approximation in the weight of the former to the theoretical demands of 

 the formula 



(which may be expressed as 



€« H; 05, 3N 02, or G,^ H,, 0„ SN^ O,), 



and the satisfactory manner in which the unavoidable production of somewhat lower 

 results in the manufacturing operations admits of practical demonstration, appear to 

 afford conclusive evidence of the correctness of either of those formulae as representing 

 the composition of the most explosive gun-cotton, and to demonstrate satisfactorily that 

 the material, prepared strictly according to the directions perfected by Von Lenk, con- 

 sists uniformly of that substance (now generally known as trinitro-cellulose) in a nearly 

 pure condition. 



The products furnished by the explosion of gun-cotton under varied conditions are 

 at present being investigated by me ; and the behaviour of the substance (as obtained 

 in ordinary manufacturing operations), when exposed to light, heat, and other agencies 

 tending to promote chemical change in bodies of unstable character, is also being care- 

 fully examined into. The results of these branches of the general inquiry into the 

 history of pyroxylin will be communicated to the Royal Society in due course ; mean- 

 while it should be stated that numerous experiments already instituted, which bear 

 upon the stability of gun-cotton, have furnished results differing in very important 

 respects from those recently published in France. 



