1009] on Guncotton and Nitroglycerine. 431 



losing its inflammability after having been dried again. A substance 

 of that description seems to be apphcable to many purposes of daily life, 

 and I should think that it might adyantageously be used as a powerful 

 means of defence and attack. Indeed, the Congreveian rockets can 

 hardly be more combustible than my prepared cotton is. What shall 

 I do with that matter ? Shall I offer it to your Government ? I 

 have enclosed a little bit of that really frightful body, and you may 

 easily convince yourself of the correctness of my statements regarding 

 its properties." 



In a subsequent letter he gave this body the name of guncotton. 



Attempts to manufacture guncotton in accordance with the method 

 devised by Schonbein were made both in this country and abroad. 

 Accidents which occurred, however, both in (xreat Britain and France 

 in the early days of manufacture, led to the abandonment of attempts 

 to produce it in these countries ; it was only in Austria that its pro- 

 duction was persevered with, and a system of manufacture worked 

 out there by Baron von Lenk. Having succeeded in producing gun- 

 cotton on the manufacturing scale, von Lenk turned his attention 

 to adapting it for propulsive purposes, and although at one time his 

 efforts appeared to have met with a certain amount of success, and 

 batteries of field artillery in Austria ^vere actually equipped with gun- 

 cotton cartridges, the difficulty of moderating its rate of combustion 

 was never satisfactorily overcome. While this question was still the 

 subject of experiments, serious accidents, due to the spontaneous 

 combustion of guncotton in store, led to its production 1)eing given 

 up even in Austria. 



In 1863, Sir Frederick Abel took up the study of the manufacture 

 of guncotton in this country with a view to adapting it for propulsive 

 purposes, and, at the same time, to improving its stability, so that its 

 spontaneous combustion in store might be prevented. 



He was not successful in the first object, but as regards the pro- 

 duction of guncotton of good stability, the modifications that he in- 

 troduced into the von Lenk system of manufacture resulted in the 

 production of stable guncotton. 



The process of manufacture devised by von Lenk was l)riefly as 

 follows : — 



Skeins of long staple cotton yarn were immersed in a mixture of 

 strong nitric acid of 1*52 sp.gr., one part, and sulphuric acid of 1 • 84 

 sp.gr., three parts, contained in iron pans. The skeins were stirred 

 about in the acid bath for a few minutes, removed to a grating above 

 it, and some of the acid squeezed out with a suitable iron tool. The 

 cotton, while still thoroughly wetted with acid, Avas transferred to 

 earthenware pots, in which it remained for 48 hours. The pots stood 

 in cold water to prevent decomposition of their contents. At the end 

 of two days the conversion of the cotton into guncotton was complete : 

 the skeins were removed from the pots, and as much as possible of 

 the acid removed in centrifugal wringing machines. After centri- 



