504 



acetic acid soltition in order to ascerfain tlie content of nnchanged 

 cyclo-liexene; the hydrogenation figure was then determined according 

 to Willstattkr's method, with active platinnm in glacial acetic acid 

 from which, after dedncting the hydrogen required for the reduction 

 of the cyclo-hexene, the benzene content could be deduced, and finally 

 the density and refraction were determined l)y way of control. 



The subjoined table gives a survey of the results obtained. 



TABLE. 



The gas drawn into the aspirator contained considerable quantities 

 of carbon monoxide ; methane was not present. 



4. In our general consideration we have assumed that at 180'' 

 and in the absence of an excess of hydrogen, benzene and cyclo- 

 hexane only could be present in admixture with methane ; we must^ 

 however, also keep account of the presence of methylcyclo-pentane, 

 the isomer of cyclo-hexane with the stable saturated o-ring. 



Nothing is known as to the relation of these two isomers at the 

 ordinary pressure. 



Aschan') certainly has found that from 70 grams of CgHj,, after 

 this had stood for two days with 140 grams of anhydrous AICI3 

 and was then boiled for 48 hours — were obtained 2.5 grams of 

 a fraction boiling below 78°, which fraction was saturated and 

 possessed the general formula Cn Hoa; fi'om this we can at most 

 draw the conclusion that it may have contained methylcyclo- 

 pentane and that the two isomers may be capable of existing for 



1) Ann. 3?,4, 12 and 85 (19U2). 



