284 



ME. ABEL'S RESEAKCHES ON GUN-COTTON. 



Soluble matter in gun-cotton prepared by seventy-two hours* treatment 



with acids 2*34 per cent. 



Soluble matter in gun-cotton submitted to a second treatment for forty- 

 eight hours with the usual acids 2 '40 „ 



Somewhat higher results were obtained by submitting the material to long-continued 

 agitation with ether and alcohol, and repeating the digestion and agitation several times 

 with fresh solvent ; but the gun-cotton became so disintegrated by this treatment, that it 

 was very difficult to filter the liquid so as to obtain it free from fibres ; it was moreover 

 found that a considerable proportion of the finely-divided mineral matter attached to 

 the gun-cotton became suspended in the liquid and could not be separated. Repeated 

 experiments showed that, after the second digestion of Waltham Abbey gun-cotton, 

 there were only very small quantities of soluble matter extracted, which it appeared 

 almost impossible to remove perfectly by this mode of treatment ; the above numbers 

 may therefore be accepted with confidence, as representing a close approximation to the 

 average proportion of matter soluble in ether and alcohol contained in the normal pro- 

 ducts of gun-cotton manufactured according to Von Lenk's prescription. 



I was led to submit the products of the Waltham Abbey manufacture to a particularly 

 searching examination, with reference to the proportion of matters extractable by ether 

 and alcohol, because an examination of several of the samples of gun-cotton obtained 

 from the Stowmarket and Hirtenberg factories, furnished results differing considerably 

 from each other and from those obtained with the first Waltham Abbey samples 

 examined. 



The following are the proportions of soluble matter found in gun-cotton manufactured 

 in Stowmarket in 1864 : — 



The variations exhibited by these numbers, and the comparatively large proportion of 

 soluble matter existing in some of the samples, must unquestionably be ascribed to some 

 irregularity in the treatment with acids, as practised at Stowmarket, due perhaps to 

 exceptional circumstances existing at the time these samples of gun-cotton were manu- 

 factured ; the examination of several products of more recent date obtained from Stow- 

 market, has furnished much more uniform results, the majority of which correspond 

 nearly to those obtained with the Waltham Abbey gun-cotton. 



