323 



this that tlie formation of acetaldehyde is not the consequence of 

 an oxidation of etliylene, e. g. according to the scheme 



H 

 C,H, + ^CH,— CH, -^ CH,Cr=0 



Hence the formation of acetaldehyde cannot have been cansed bj 

 the possible presence of small rpiantities of air in the ethylene used. 



We are, therefore, of opinion that we are justified in concluding 

 that a primary addition of water to . the double bond has taken 

 place, and that the reaction : 



C,H,OH^C,H, + H,0 



may accordingly be considered as a reversible reaction. 



We have obtained perfectly analogous results with mixtures of 

 proftylene and water-vapour. At 350° and in the presence ofalumi- 

 niumhydroxide acetone was then formed in a quantity of from 

 0,2 to 0,3 "!, of the propylene. In our opinion the primary- 

 formation of isopropylalcohol by addition of water to propylene, 

 must be assumed in this case. Afterwards the isopro|)ylalcoliol 

 is transformed to acetone through the splitting otï of hydrogen. 

 Hence the direct addition of water proceeds analogously to the 

 addition of hydriodic acid, in which likewise the isopropyl compound 

 appears. Accordingly the rule of Markonikow remains valid also in 

 this case. 



On the ground of these results it is probable that the addition 

 of water to propylene and ethylene can take place under high 

 pressure at temperatures far below 300°. We have, however, made 

 no experiments in this direction. 



^ 2. Tke Hydration of Ethylene and Propylene by 

 Means of Acids. 



The syntheses of ethyl- and isopropylalcohol from ethylene and 

 propylene by the formation of alkyl-sulphuric acid, and subsequent 

 hydrolysis, by M. Berthblot ') are among the classic syntheses of 

 organic chemistry. Berthhi.ot investigated the absorption of these 

 olefines by pure sulphuric acid of 98 — 99 V, H,SO, at ordinary 

 temperature. Afterwards the absorption of ethylene by sulphuric acid 

 has been repeatedly studied. Particularly in the last few years several 

 technical chemists have made experiments to absorb the ethylene from 



•) Berthelot: Chitnie organique fondée sur la synthese, p. 115. c, f. Ann. de 

 Chimie et de Physique. (7), 4, 101 (1895). Bull. Soc. Ghim. XI, 13. (1869). 



