THE SCIENTIST 181 



state of society. An explosion took place which has 

 done me no other harm than that of preventing me 

 from working this day and the effects of which will 

 be gone to-morrow and which I should not mention 

 at all, except that you may hear some foolish exag- 

 gerated account of it, for it really is not worth men- 

 tioning. . . ." The compound on the investigation 

 of which he was then engaged is now known as the 

 trichloride of nitrogen. 



In the autumn of 1813 Sir Humphry and Lady 

 Davy, accompanied by Michael Faraday, who on 

 Davy's recommendation had in the spring of the 

 same year received a post at the Royal Institution, 

 set out, in spite of the continuance of the war, on a 

 Continental tour. At Paris Sir Humphry was wel- 

 comed by the French scientists with every mark of 

 distinction. A substance which had been found in 

 the ashes of seaweed two years previously, by a soap- 

 boiler and manufacturer of saltpeter, was submitted 

 to Davy for chemical examination. Until Davy's 

 arrival in Paris little had been done to determine 

 its real character. On December 6 Gay-Lussac pre- 

 sented a brief report on the new substance, which 

 he named iode and considered analogous to chlorine. 

 Davy, working with almost incredible rapidity in 

 the presence of his rivals, was able a week later to 

 sketch the chief characters of this new element, now 

 known by the name he chose for it ioduic. 



We have passed over his investigation of boracic 

 acid, ammonium nitrate, and other compounds ; we 

 can merely mention in passing his later studies of 

 the diamond and other forms of carbon, of the 

 chemical constituents of the pigments used by the 



