316 



A corresponding bromide is formed when bromine is added to 

 stannic bis-ethyl. It is an oily body, with an irritating odour. 

 When acted upon by ammonia, an oxide is precipitated, which with 

 acids forms beautiful crystallizable salts, readily soluble in water. 



A complete history of these salts, and their decompositions with 

 zinc-ethyl, will possess much interest, and may prove of value in 

 referring to a few simple radicals the numerous complex bodies 

 described by Lowig, &c. 



The author is at present engaged on this branch of the inquiry, 

 a detailed account of which he hopes to embody in a communication 

 to the Royal Society, the present paper being intended only as an 

 outline to be hereafter filled in. 



In conclusion, the author would remark that a rich harvest can 

 scarcely fail to be reaped, from submitting to the action of zinc-ethyl 

 the metallic compounds of other groups, such as arsenic, bismuth, 

 and antimony. 



XIV. " Preliminary Notice of Additional Researches on the 

 Cinchona Alkaloids." Part III. By W. BIRD HERAPATH, 

 M.D. &c. Communicated by Professor STOKES, Sec. R.S. 

 Received June 17, 1858. 



Since the author had the honour of presenting to the Royal 

 Society his paper entitled " Researches on the Cinchona Alkaloids," 

 Parts I. and II., he has been much occupied with a continuation of 

 the subject, and he has arrived at important results, which, although 

 in an unfinished state, he hastens to lay before the scientific world, 

 in order to assure himself of the priority of discovery. 



Having had occasion to make some experiments upon the rotatory 

 power of the /3-quinidin mentioned in the first part of his paper, he 

 arrived at the conclusion that some other feebly dextro- gyrate alka- 

 loid accompanied it, and of a more soluble and less crystallizable 

 character. Consequently, on its further purification by frequent re- 

 crystallization from alcohol, the quinidin was obtained perfectly pure ; 

 it then had the molecular rotation assigned to it by Pasteur, namely 

 250' 75|( . Two examinations have given the following elements : 



I. Its solution having been made in rectified spirit of 83 6 by boiling, 



