1865.] On the Synthesis of Tribasic Acids. 77 



ing to it ; but the analogies which connect aluminium with other metals 

 are so close and so numerous, that there are probably few' metals of which 

 the position in our classification is more satisfactorily settled. We may 

 safely trust that the able investigators who are examining these interesting 

 compounds will bring them more fully than now within the laws which 

 regulate the combining proportions of their constituent elements*; for, as it 

 now stands, the anomaly is far less than many others which have been 

 satisfactorily explained by further investigations. 



Meanwhile aluminium is a metal singular for only appearing in that 

 pseudo-triatomic character in which iron and chromium appear in their 

 sesquisalts. 



February 16, 1865. 



Dr. W. A. MILLER, Treasurer and Vice-President, in the Chair. 

 The following communications were read: 



I. " On the Synthesis of Tribasic Acids." By MAXWELL SIMTSON, 

 M.D., F.R.S. Received January 25, 1865. 



(Abstract.) 



In a former Number of the ' Proceedings ' * I gave a preliminary notice of 

 a tribasic acid having the composition C 12 H 8 O 12 , formed by the action of 

 potash on tercyanide of allyle. The process for the preparation of the 

 acid given in that paper I have since succeeded in improving very consider- 

 ably, so that I can now obtain it in quantity and with tolerable facility. 

 An account of the improved process is contained in the general paper which 

 accompanies this abstract. The paper also contains a description of the 

 crystalline form of the acid, for which I am indebted to Professor Miller of 

 Cambridge. 



M. Kekulef proposes to call this body carballylic acid. This name I 

 cannot, however, accept without some modification, as recent researches 

 have proved that it belongs by right to crotonic acid. I propose therefore, 

 in order to avoid confusion, to call it ^rzcarballylic acid. 



Since the appearance of my preliminary paper, I have also prepared and 

 analyzed several of the salts and ethers of this acid, of which the following 

 is a short account. 



Tricarballylic Ether, C f l Af( a "' \ O 6 . 



This ether is readily prepared by conducting a stream of dry hydrochloric 

 acid gas into a solution of tricarballylic acid in absolute alcohol. The pro- 

 duct obtained on evaporating the alcohol distils between 295 and 305 C. 



* Proceedings of the Royal Society, vol. xii. p. 236. 

 t Lehrbuch der Organischen Chemie, vol. ii. p. 187. 

 J Annalen der Chemie und Pharmacie, vol. cxxxi. p. 58. 



