ALCOHOLS. 273 



or Indian corn ; Irish whiskey, from potatoes ; Scotch whiskey, 

 from barley; brandy or cognac, by distilling French wines; rum, 

 by fermenting and distilling molasses; arrack, from fermented 

 rice; gin, from various grains flavored with juniper berries. 



Amyl alcohol, C 5 H U HO. This alcohol is frequently formed in 

 small quantities during the fermentation of corn, potatoes, and 

 other substances. When the alcoholic liquids are distilled, 

 amyl alcohol passes over towards the end of the distillation, 

 generally accompanied by propyl, butyl, and other alcohols, and 

 by certain ethers and compound ethers. A mixture of these 

 substances is known as fusel oil, and from this liquid amyl 

 alcohol may be obtained in a pure state. It is an oily, colorless 

 liquid, having a peculiar odor, and a burning, acrid taste; it is 

 soluble in alcohol but not in water. By oxidation of amyl 

 alcohol, valerianic acid is obtained. 



Glycerine, Glycerinum, C 3 H 5 3HO = 92. Glycerine is the triatomic 

 alcohol of the residue glyceryl, C 3 H 5 , formed by removal of 

 three atoms of hydrogen from the saturated hydrocarbon pro- 

 pane, C 3 H 8 , and by combination of the residue with three times 

 HO. 



Glycerine is a normal constituent of all fats, which are gly- 

 cerine in which the three atoms of hydrogen of the hydroxyl 

 have been replaced by residues of fat acids. When fats are 

 treated with alkalies, these latter combine with the fat acids, 

 whilst glycerine is liberated. Upon this decomposition, carried 

 out on a large scale in the manufacture of soap, depends the 

 mode of obtaining glycerine. 



Pure glycerine is a clear, colorless, odorless liquid of a syrupy 

 consistence, oily to the touch, hygroscopic, very sweet, and 

 neutral in reaction, soluble in- water and alcohol in all propor- 

 tions, but insoluble in ether, chloroform, benzol, and fixed oils; 

 its specific gravity is 1.255 ; it cannot be distilled by itself 

 without decomposition, but is volatilized in the presence of 

 water, or when hot steam is allowed to pass through it. 



Phenoles. The substances termed phenoles are formed by re- 

 placement of hydrogen by hydroxyl in the aromatic hydrocar- 

 bons of the benzene series ; they have the constitution of alcohols, 



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