102 



Mr. Abel on Gun-cotton. 



[Apr. 19, 



duct and of tlie vasa deferentia. Harvey, who was opposed to the notion 

 of Fabricius, expresses the opinion that an intercourse once or twice repeated 

 might suffice to impregnate a whole bunch of yelks, he having found that 

 an egg laid on the 20th day of seclusion of a hen produced a chick*. This 

 fact is an interesting one, however explained. It might be adduced in 

 favour of the opinion of Fabricius ; but inasmuch as the passage of the 

 fully-formed egg in the act of expulsion does not necessarily secure the 

 expulsion of any spermatozoa previously received into the oviduct, it is of 

 little value in the argument : and here I may mention that I have detected 

 spermatozoa in the oviduct, even in that portion in which the egg was re- 

 ceiving its calcareous incrustation. 



III. Researches on Gun-cotton. — Memoir I. Manufacture and Com- 

 position of Gun-cotton.^' By F. A. Abel, F.R.S., V.P.C.S. 



Eeceived April 10, 1866. 



(Abstract.) 



A review of the researches on the production, properties, and composition 

 of gun-cotton hitherto published, and a brief examination into the pro- 

 bable causes of the discrepancies exhibited between the results and con- 

 clusions of different experimenters, ai'e followed in this paper by a criti- 

 cism of the several steps in the system of manufacture of gun-cotton, as 

 prescribed by Baron v. Lenk. 



The conclusions arrived at on this subject are founded upon carefully 

 conducted laboratory- experiments, and upon extensive manufacturing 

 operations carried on during the last three years at the Royal Gunpowder 

 Works, Waltham Abbey. In some of these operations v. Lenk's system 

 of manufacture, as originally communicated to the English Government 

 by that of Austria, was strictly followed ; in others, various modifications 

 were introduced in different stages of the manufacture — such as in the 

 composition of the acids used, in the proportion borne by the cotton to 

 the acids in which it remained immersed, in the duration of the treat- 

 ment of cotton with the acids, and in the methods of purification to which 

 the gun-cotton was submitted. 



Exception is taken to one or two points in the general system of manu- 

 facture, and directions are indicated in which they may be advantageously 

 modified ; but the general conclusion arrived at is that, although Baron 

 v. Lenk cannot be said to have initiated any new principle as applied to 

 the production of gun-cotton, he has succeeded in so greatly perfecting 

 the process of converting cotton into the most explosive form of pyroxyline 

 or gun-cotton, and also the methods of purification, as to render a simple 

 attention to his clear and definite regulations alone necessary to ensure the 



* Opera Omnia, a Col. Med. Lond. ed. 1766, p. 206. 



