( 11^ ) 



vapour mixed with hydrogen is passed at 125° — 130** over nickel 

 reduced to a low temperature, the hydrogen is eagerly absorbed and 

 a product with a lower boiling point is obtained, which, however, 

 contains small quantities of unsaturated compounds (perhaps also 

 cyclic ones). In order to remove these, the product was treated 

 with bromine and after remoxal of the excess and further purification 

 it was fractionated. As a main fraction, there was obtained a liquid 

 boiling at 68°.5— 69°.5 at 759.7 mm. 



Sp. gr.,,o = 0,6907 nij,,^ = 1.3919. 



Although the boiling point agrees with that of the expected hexane 

 the sp. gr. and the refraction differ still too much from the values 

 found for hexane by Brühl and by Eykman ^). 



Therefore, the product obtained from hexatriene was shaken for 

 some time with fresh portions of fuming sulphuric acid until tliis 

 was no longer coloured. After this treatment were obtained 

 one fraction of 



B. p. 69°-70°, Sp.gr.,, 0.6718 njj,, 1.38250. 

 and another of 



B. p. 69°.7— 70°5, Sp.gr.,^ 0.6720, ud,, 1.38239. 



An n-hexane prepared in the laboratory, according to Beühl ^) by 

 Mr. ScHERiNGA gave the following values 



B.p. 69°, Sp.gr.,, 0.664 nn,, 1.3792 

 whilst an ?z-hexane prepared, from diallyl according to Sabatier and 

 Senderens, by Mr. Sinnige gave 



B.p. 68.5°— 70,° Sp.gr.,, 0.6716, 71d,, 1.38211. 



It is, therefore, evident that the hexane obtained b}' Sabatier's, and 

 Senderens' process still contains very small traces of impurities. 



There cannot, however, exist any doubt that 1-3-5-hexatriene 

 absorbs 6 atoms of hydrogen with formation of normal hexane. 



Of greater importance, however, for the knowledge of the new 

 hydrocarbon is the reduction by means of sodium and absolute 

 alcohol. 



If, as a rule, unsaturated hydrocarbons are not likely to take up 

 hydrogen under these circumstances, it becomes a different matter 

 when a conjugated system is present. Now, in 1-3-5-hexatriene, two 

 conjugated systems are found and we might therefore expect the 

 occurrence of a 2-4-hexadiene : 



CH,— CH=CH— CH=:CH— CH, 



1) Brühl (B. B. 27, (1894) 1066) finds Sp.gr..t^ - 0.6603, nD.n = 1.3734.; 

 Eykman (R. 14, (1881) 187) Sp.gr.^^ - 0.6652 nOu - 1.37725. 



2) Ann. 200. 183. 



