268 SCIENCE PROGRESS 



The action of acetone on isopropylic alcohol, 1 however, is 

 simple, consisting merely in a synthetic or additive change, a 

 pinacone being formed : 



8S:> co+ ™:> choh -* c£> c < oh >- c < oh ><ch, 



Pinacone. 



Benrath 2 found that benzaldehyde combines with quinoline 

 and quinaldine to form compounds of the following structure : 



a 



From quinoline. From quinaldine. 



ch r^Y" CH 



,CH 2 l s J Sv ^C.CH 2 .CH(OH).C 6 H 5 



N . CO . C 6 H 5 N 



The different character of the action in the two cases is very 

 striking. Benzaldehyde combines with cinnamic acid in still 

 another manner, a complex product being formed by elimina- 

 tion of carbon dioxide and hydrogen : 



C 6 H 5 .CHO OH .CO. CH : CH . C 6 H 5 



+ -> 



C 6 H 5 .CHO OH.CO.CH:CH.C 6 H 5 



C 6 H 5 .CO.CH.,.CH.C 6 H 5 



| + H 2 + 2CO, 



C 6 H 5 .CO.CH,.CH.C 6 H 5 



In view of the production of hydrogen cyanide in the early 

 stages of plant growth, Ciamician and Silber have made a 

 number of experiments on the effect of light on the action of 

 hydrogen cyanide on aldehydes and ketones. Contrary to ex- 

 pectation, the cyanhydrol of aldehyde was not affected by light 

 but acetone 3 in presence of hydrogen cyanide gave much 

 soluble gummy matter " recalling the peptones in chemical and 

 physical properties " together with a-hydroxybutyric acid, 

 OH.CMe 2 .C0 2 H, and its amide, OH . CMe 2 . CO . NH 2 , but 

 as main products : 



1 Atti R. Accad. Lincei, 191 1, 20, i. 714 ; Bar. 1911, 44, 1280. 



* J.pr. Chem. 1906, 78, 383. 



3 Atti R. Accad. Lincei, 1906, 15, ii. 529; Ber. 1905, 38, 1671. 



