382 Kolbc and Lautcmann on Salicylic Acid and its Homologues. 



When the above body is heated in a sealed tube with baryta 

 water, it is converted into ammonia and the acid: 



^H^N^O+H^Grr^^NO^ + NH 3 . 



Carbopyrrolamide. Carbopyrrolic 



acid. 



The product of the action is carbopyrrolate of barium, which 

 crystallizes in nacreous laminae. It can be boiled with potash 

 without decomposition, but when treated with hydrochloric acid, 

 a white crystalline precipitate of carbopyrrolic acid is formed. 



When the free acid is heated at 60° an atom of carbonic acid 

 is liberated, and the brown flocculent substance is separated 

 which Anderson calls pyrrol-red. The decomposition is as 

 follows : 



€ 5 H 5 N0 2 =C0 2 +€ 4 H 5 N. 



This action is quite analogous to the decomposition of anthra- 

 nilic acid by destructive distillation, 



Kolbc and Lautemann have published a memoir on the con- 

 stitution of salicylic acid*. They consider that this acid is ana- 

 logous to lactic acid, and monobasic. For the development of 

 their reasons, which by no means settle the question, the original 

 memoir must be consulted ; we shall here merely describe cer- 

 tain new bodies which they have discovered in the course of their 

 investigation, 



The starting-point for their research was salicylic acid. This 



acid has the formula C 14 H 6 O 6 , and is isomeric with oxybenzoic 



acid. The authors consider both these acids as having the same 



TC 12 fl 4 "1 

 rational formula, which they write HO,^ n ^ 2 >C 2 2 , 0, 



but as containing two different radicals. Benzoic alcohol and 

 cresylic alcohol have the same composition, C 14 H 8 O 2 , and doubt- 

 less the same constitution, but they differ in containing different 

 radicals. In like manner, in salicylic acid the radical is phenyle, 

 C 12 H 5 , while in oxybenzoic acid there is a radical of an alcohol 

 next lower in the series than benzoic alcohol. 



When one part of salicylic acid is mixed with three parts of 

 pentachloride of phosphorus, a violent action is set up, torrents 

 of hydrochloric acid are evolved, and a colourless liquid distils 

 over, which consists principally of the chloride C 14 H 4 O 2 CI 2 , and 

 of oxychloride of phosphorus. Besides these there is some 

 chloride of salicyle, C 14 H 5 4 C1, and an oil which is unacted 

 on by water. 



The chloride, C 14 H 4 O 2 CI 2 , is obtained in larger quantity by 



* Liebig's Annalen, August 1860. 



