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LXXII. Chemical Notices from Foreign Journals. 



%E. Atkinson, Ph.D., F.C.S. 



[Continued from p. 380.] 



HERRMANN* has investigated the action of nascent hydro- 

 gen on benzoic acid. When an excess of this acid in 

 water is heated nearly to boiling, and sodium-amalgam added, 

 the nascent hydrogen is almost entirely consumed ; and if neu- 

 tralization and solution of the acid are prevented by the gradual 

 addition of hydrochloric acid, the following changes occur : the 

 liquid smells strongly of oil of bitter almonds; during the ad- 

 dition of the hydrochloric acid benzoic acid separates along with 

 an oily body ; as the reaction continues, the former finally dis- 

 appears, while the latter alone remains in solution. 



When, in the course of the above reaction, the liquid had 

 become alkaline, it was distilled until the odour of oil of bitter 

 almonds was no longer perceived. In this way an aqueous dis- 

 tillate was obtained containing oil-drops ; on shaking this with 

 ether, and subsequently distilling off the ether, an oily liquid 

 was obtained which proved to be benzylic alcohol, C 14 H 8 O 2 , the 

 formation of which from benzoic acid is thus expressed : — 



C 14 H 6 4 + 4H = 2HO + C 14 H 8 2 . 



By exhausting the alkaline residue in the above case with 

 ether, a heavy aromatic oil was obtained, which after some time 

 solidified to a crystalline magma. 



The liquid from which this had been extracted by ether was 

 returned to the retort, and again treated with sodium-amalgam 

 until an oil was separated which did not solidify in the cold. 



The above crystalline substance, when boiled with water, was 

 partly dissolved ; on cooling, a body was obtained which crys- 

 tallized in lamina*. The melting-point of this substance is 116°; 

 it is unaltered by boiling with potash, but by destructive 

 distillation is resolved completely into oil of bitter almonds. 

 The body has the formula C 28 H 14 4 , and is isomeric with hy- 

 drobenzoin, obtained by Zinin by the action of zinc and sul- 

 phuric acid on oil of bitter almonds. From its formula it might 

 be a compound of benzoic aldehyde with an aldehyde richer by 

 two atoms of hydrogen. 



The third substance separated from the alkaline solution by 

 hydrochloric acid is a volatile oily acid with an extremely un- 

 pleasant odour, strongly suggestive of valerianic acid. It forms 

 salts, which cannot be crystallized, but readily attract moisture, 

 and are decomposed on exposure to the air in consequence of 

 oxidation of the acid. As it was impossible to get good results 



* Liebig's Annalen, October 1864. 





