14 



Dr. Hofmann 071 Aniline-blue. 



[N6v. 26, 



showing that the frequent repetition of the process of ethylation had pro- 

 duced, not the Jiydriodate of triethylic rosaniliney hut the ethyliodate of 

 this substance, — a result which appeared particularly welcome, inasmuch 

 as it threw at the same time considerable light upon the degree of substi- 

 tution which belongs to rosaniline itself. 



The facts elicited by the study of the action of iodide of ethyl upon 

 rosaniline open a new field of research, which promises a harvest of re- 

 sults. The question very naturally suggests itself, \\Tiether the substitution 

 for hydrogen in rosaniline of radicals other than methyl, ethyl, and amyl, 

 may not possibly give rise to colours differing from blue ; and whether 

 chemistry may not ultimately teach us systematically to build up colouring 

 molecules, the particular tint of which we may predict with the same 

 certainty with which we at present anticipate the boiling-point and other 

 physical properties of the compounds of our theoretical conceptions ? 



This idea appears to have floated in the mind of M. E. Kopp when, 

 with remarkable sagacity, he concluded his paper on Aniline-red* in the 

 following terms : — " The hydrogen of this substance being replaceable 

 also by methyl, ethyl, and amyl, &c., we may anticipate the existence of a 

 numerous series of compounds, all belonging to the same type, and which 

 might constitute colouring matters either red, or violet, or blue." 



Conceptions which only two years ago appeared little more than a 

 scientific dream, are now in the very act of accomplishment. 



I propose to continue these researches, and intend in a later com- 

 munication to submit to the Royal Society the results obtained in the 

 study of two other colouring matters derived from rosaniline, viz. aniline- 

 green and aniline-violet. 



November 26, 1863. 



Major-General SABINE, President, in the Chair. 



In accordance with the Statutes, notice was given from the Chair of the 

 ensuing Anniversary Meeting, and the list of Officers and Council proposed 

 for election was read as follows : — 



President. — Major-General Edward Sabine, R.A., D.C.L., LL.D. 



Treasurer.— WiWmm Allen Miller, M.D., LL.D. 



_ J William Sharpey, M.D., LL.D. 

 iiecretaries. ^ ^^^^^^ Stokes, Esq., M.A., D.C.L. 



Foreign Secretary. — Prof. Wilham Hallows Miller, M.A. 



Other Members of the Council— James Alderson, M.D. ; George Busk, 

 Esq., Sec. L.S.; Col.SirGeorgeEverest,C.B.; Hugh Falconer, M.A.,M.D.; 



* Ann. de Chim. et de Phys. [3] Ixii. 230. 



