1867.] 



of the Series C'^ H-'^^^^ 



37 



The small quantity of mother-liquor from these crystals was precipitated 

 with nitrate of silver, and the precipitate crystallized from boiling water. 



0*2120 of this silver-salt gave 0*1374 of silver, or 64*72 per cent. ; ace- 

 tate of silver contains 64*67 per cent, of silver. 



By oxidizing di-isopropyl with chromic acid the only products formed 

 are therefore carbonic acid and acetic acid. 



2. Amyl-isopropyl, C^H^g. 



This hydrocarbon was obtained by acting with sodium and ether upon a 

 mixture of iodide of isopropyl and iodide of amyl. The reaction sets in 

 without applying heat, and is rather violent in the beginning, and it is 

 therefore necessary to keep the flask first immersed in cold water ; but to 

 complete the decomposition the mixture has to be heated. "When all the 

 sodium has disappeared, the contents of the flask are distilled from an oil- 

 bath, and the distillate is heated with sodium as long as iodide of sodium 

 is formed. Ether and non-attacked iodides are then removed by treating 

 the liquid with strong acids as described above, and thus a mixture of di- 

 isopropyl, amyl-isopropyl, and di-amyl is obtained, from which these hydro- 

 carbons can easily be separated by fractional distillations. 



Amyl-isopropyl is a colourless liquid boiling at 109°-110°; its specific 

 gravity was found 



at 16°*5'C. = 0*6980, 

 at 49° C. = 0-6712. 

 The results of the analysis are, — 



2040 of substance gave 0-6285 of carbonic acid and 0*2900 of water. 





Calculated. 



Found. 





. . 96 84-2 



84*0 



H, . . 



. . 18 15-8 



16*1 





114 1000 



100*1 



The constitution of this hydrocarbon can be expressed by the formula 



r H 



C \ , and it might therefore be called dimethyl-amyl-methan. Its 



boiling-point and its specific gravity coincide perfectly well with those of 

 dibutyl, which according to Kopp boils at 109°, and has at 16°*4 the spe- 

 cific gravity 0*7001 I believe that these two hydrocarbons are identical ; 

 for Erlenmeyer stated a short time ago in a prelimin?iry note, that he 

 has found that the butyl-alcohol formed by fermentation is methyl-alcohol, 

 in which one atom of hydrogen in the methyl is re[)laced by isopropyl, 

 and that fermentation amyl-alcohol is ethyl-alcohol, in which also one 

 atom of hydrogen in the methyl group is replaced by isopropyl f. If this 

 view is correct, amyl-isopropyl must be identical with dibutyl, as the follow- 

 ing formulae clearly show : — 



* Ann. der Cliem. und Pbarm. vol. xcv. p. 336. 



t Zeitschrift fur Chem. N. F. vol. ill. p. 117. 



