1863.] 



Presidenfs Address. 



31 



material was first introduced by Schonbein in 1846, its distinctive qualities 

 in comparison with gunpowder were recognized, although at that period 

 they were far less well ascertained by experiment than they are at present. 

 To the employment of gun-cotton as then known there was, however, a 

 fatal drawback in its liability to spontaneous combustion. The elaborate 

 experiments of General von Lenk have shown that this liability was due to 

 imperfection in its preparation, and ceases altogether when suitable pro- 

 cesses are adopted in its manufacture. Perfect gun-cotton is a definite 

 chemical compound ; and certain processes for the removal of all extra- 

 neous matter and of every trace of free acid are absolutely indispensable. 

 But when thus prepared it appears to be no longer liable to spontaneous 

 combustion, it can be transported from place to place with perfect secu- 

 rity, or be stored for any length of time without danger of deterioration. 

 It is not impaired by damp — and may be submerged without injury, its 

 original qualities returning unchanged on its being dried in the open air 

 and at ordinary temperatures. 



A scarcely less important point towards the utilization of gun-cotton 

 and the safety with which it may be employed in gunnery is the power of 

 modifying and regulating its explosive energy at pleasure, by means of 

 variations in the mechanical structure of the cartridge, and in the relative 

 size of the chamber in which it is fired. 



The experiments made by the Austrian Artillery Commission, as well as 

 those for blasting and mining, were conducted on a very large scale ; with 

 small arms the trials appear to have been comparatively few. 



There can be no hesitation in assenting to and accepting the concluding 

 sentence of the Committee's report. "The subject has neither chemically 

 nor mechanically received that thorough investigation that it deserves. 

 There remain many exact measures still to be made, and many important 

 data to be obtained. The phenomena attending the explosion of both 

 gun-cotton and gunpowder have to be investigated, both as to the tempe- 

 ratures generated in the act of explosion and the nature of the com- 

 pounds which result from them, under circumstances strictly analogous to 

 those which occur in artillery practice.^' 



I proceed to announce the awards which the Council has made of the 

 Medals in the present year; and to state the grounds on which those 

 awards have been made. 



The Copley Medal has been awarded to the Reverend Adam Sedgwick, for 

 his observations and discoveries in the Geology of the Palaeozoic Series of 

 Rocks, and more especially for his determination of the characters of the 

 Devonian System, by observations of the order and superposition of the 

 Killas Rocks and their Fossils, in Devonshire. 



Mr. Sedgwick was appointed Woodwardian Professor of Geology in the 

 University of Cambridge in the year 1818, since which time, up to a 

 recent period, comprising an interval of upwards of forty years, he has 



