112 



February 21, 1861. 



Major-General SABINE, R.A., Treasurer and Vice-President, 

 in the Chair. 



The following communications were read : 



I. "On Terephthalic Acid audits derivatives." By WARREN 

 DE LA RUE, Ph.D., F.R.S. &c., and HUGO MULLER, 

 Ph.D., F.C.S. Received February 7, 1861. 



"Whilst pursuing our investigation of Burmese naphtha, an abstract 

 of which we have already communicated to the Society, we noticed, 

 among the products of the action of nitric acid on certain liquid 

 hydrocarbons contained in Rangoon tar, an acid of peculiar pro- 

 perties. A very lengthened investigation of this acid and its de- 

 rivatives we are about bringing to a close ; but as the drawing up of 

 this account will necessarily occupy a considerable time, we have 

 thought it desirable to send a short abstract of the chief results we 

 have obtained, with the view of its appearing in the * Proceedings ' of 

 the Society. 



M. Caillot, about fifteen years ago, obtained a peculiar acid 

 among the products of the action of dilute nitric acid on oil of tur- 

 pentine, to which he gave the name of Terephthalic acid, on account 

 of its generation from oil of turpentine and its isomerism with 

 phthalic acid. M. Caillot' s account of his new acid was so 

 brief and incomplete, that, although we recognized many points of 

 resemblance between it and the acid we had obtained from Burmese 

 naphtha, we were compelled to repeat his experiments on oil of 

 turpentine before we could fix with certainty the identity of the two 

 products. In the course of these experiments, in which that 

 identity was fully established, we noticed some interesting features 

 in the compounds of the acid and the derivatives we discovered ; 

 more especially the relation of terephthalic acid to the well-known 

 aromatic series, a relation precisely analogous to that which suc- 

 cinic acid bears to the fatty acids. The close relation which exists 

 between terephthalic acid and benzoic acid is most strikingly mani- 

 fested in the great number of derivatives which are obtained from 

 the former ; indeed, nearly all of the most characteristic benzoyl- 



