522 



FUSEL OIL 



may bo easily separated by the tap-funnel. After drying over chloride of calcium, it 

 is to be again rectified once or twice, only that portion distilling at about 269 0l G Fahr. 

 (132 Cent.) being received. The product of this operation is pure amylic alcohol, 

 from which an immense number of derivations of the amylic series can bo obtained. 

 By treatment with sulphuric acid and bichromate of potash it is converted into vale- 

 rianic acid. In this manner all the valerianic acid, now so much employed in 

 medicine, is prepared. By distilling amylic alcohol with sulphuric jicid and acetate 

 of potash, we obtain the acetate of amylo, commercially known as jargonelle-pear 



The foreign fusel oils obtained from the grape-marc contain several homologues higher 

 and lower in the series than the amylic alcohol. In fact, it would appear that during 

 the fermentation of grapes there are formed, not only alcohols, but ethers and acids. 



M. Chancel, by repeatedly rectifying the dehydrated and more volatile portions of 

 the residues of the distillation of grape-marc alcohol, succeeded in isolating a fluid 

 boiling at 205 Fah.r. This proved to be true propionic alcohol. M. Wurtz has also 

 been able to obtain the butylic alcohol by rectifying certain specimens of potato oil. 



All fusel oils are not so complex. The author of this article has repeatedly examined 

 specimens of English and Scotch fusel oil, which did not contain anything save the 

 othylic and amylic alcohols, accompanied by small portions of the acids, which are 

 procured by their oxidation. M. Chancel has given the following equations, which 

 explain the manner in which saccharine matters break up into homologous alcohols 

 under the influence of ferments. I have reduced the unitary notation employed by 

 him into the ordinary formulae used in this country, in order to render the relations 

 as clear as possible to the reader. 



2C 12 H 12 12 = SCO 2 + 4C 4 H a 2 . 

 Glucose. Alcohol. 



2C 1S H 12 12 = 8C0 2 + C 4 H 8 2 + 2C 8 H 8 2 + 2HO. 



Propionic alcohol. 

 2C 12 H 12 12 = 8C0 2 + 2C 8 H 10 2 + 4HO. 



Butylic alcohol. 



2C 12 H >2 12 = SCO 2 + C 6 H 8 2 + C'H 12 2 + 4HO. 

 Amylic alcohol. 



M. Chancel appears to consider the last equation as indicating the necessity of pro- 

 pionic alcohol being always formed wherever amylic alcohol is generated ; but this is 

 not in accordance with the results of those chemists who have examined crude amylic 

 alcohol repeatedly for propionic alcohol, but without finding any. The formation of 

 these interesting homologues appears therefore to depend upon special circumstances 

 connected with the fermentation. 



The caproic alcohol is also contained in certain varieties of fusel oil. 



In order to assist those who may wish to examine the fluid alluded to, the following 

 table of the physical properties of the alcohols, up as high as the caproic, has been 

 inserted : 



Table of the Physical Properties of some Homologous Alcohols found in Fiuel Oils. 



Fusel oil, in addition to these homologous alcohols, contains fatty acids. The 

 following list contains the acids found in fusel oil, with the name of the observer : 



