310 M. Michaelson on Propylic and Butylic Aldehydes. 



qb jt5 rO 

 propylic aldehyde, „ |»; and that the substance was not 



acetone, which has the same formula, was proved by the fact 

 that it reduced silver with formation of propionic acid. The 

 residue in the retort, as mentioned above, was found on rectifi- 

 cation to boil between 73° and 77°. The analysis and the 

 vapour-density determination of this substance, together with its 

 chemical deportment, left no doubt that it was butylic aldehyde, 

 C 4 H 8 0. 



The same chemist has investigated the products of the oxida- 

 tion of butylic alcohol. He found it impossible, by fractional 

 distillation of fousel oil, to obtain a pure butylic alcohol. But 

 by converting the fractions containing most butylic alcohol into 

 iodide and fractionizing these, he obtained pure iodide of butyle. 

 This was first converted into acetate of butyle, and this, by 

 decomposition with potash, into butylic alcohol. 



When this butylic alcohol was oxidized with bichromate of 

 potash and sulphuric acid, it yielded propylic and butylic alde- 

 hydes, and carbonic, propionic, and butyric acids. Hence 

 chromic acid oxidizes not merely the hydrogen, but also part of 

 the carbon, which is converted into carbonic acid. 



When acetic or benzoic acid or their homologues are distilled 

 with excess of alkali, they decompose into carbonate and a hydro- 

 carbon which contains an atom of carbon less than the acid : 

 thus benzoic acid, G 7 H 6 O 2 , gives carbonic acid, GO 2 , which 

 combines with the base, and benzole, € 6 H 6 . Harnitz-Harnitzsky* 

 has succeeded in performing the inverse operation of passing 

 from benzole to benzoic acid. Chlorocarbonic acid was passed 

 into a retort, which was heated and exposed to the light at the 

 same time that benzole vapour also entered. This retort was 

 connected with a condensing arrangement. The reaction took 

 place only with the vapour of benzole ; it was accompanied by 

 the disengagement of hydrochloric acid gas. 



The product of the reaction was separated by distillation from 

 the unattacked benzole. It was found to boil constantly at 198°. 

 This fact and its other properties left no doubt that it was chlo- 

 ride of benzoyle ; thus 



gene + G0C1 2 = Q 7 H 5 0C1 + HC1. 



Benzole. Chlorocarbonic Chloride of 



acid. benzoyle. 



When this substance was dropped in water it sank to the bot- 

 tom, and was gradually changed into a crystalline mass which 



* Comptes Rendus, vol. lviii. p. 748. 



