SUBSTITUTION PRODUCTS OF THE HYDROCARBONS 37 



is distilled without attempting to secure complete purification 

 of the distillate or the highest per cent of alcohol possible, there 

 is obtained a strong alcoholic distillate possessing certain 

 characteristic properties due to the original material used. 

 These liquids constitute the distilled liquors known as whisky^ 

 brandy, cognac, gin, rum, etc. These liquors are much stronger 

 in alcohol than either wine or beer and contain usually from 

 35 per cent to 40 per cent alcohol. 



Industrial Uses. — The importance of alcohol is not, how- 

 ever, in its use in one of these various forms as a beverage, but 

 in its wide application in the arts as a solvent or as a substance 

 from which other valuable compounds are made. In some of 

 its industrial uses it may be replaced by its methyl homologue, 

 but not in all, at least to advantage. In its synthetical uses it, 

 of course, cannot be replaced by the other. 



Taxation. — Because of its use in beverages, which are almost 

 wholly luxuries, nearly all civilized countries have considered 

 alcohol as a proper article for taxation and for government 

 control. The tax is also usually high, so that the cost of pure 

 alcohol is far above its cost of actual manufacture. Alcoholic 

 beverages, and pure alcohol, that are subject to such taxation 

 are taxed according to the amount of pure alcohol present. It 

 therefore becomes necessary to determine the strength of 

 alcoholic liquids and also to have a fixed standard of strength. 

 The analysis of such liquids for per cent, of alcohol has had much 

 attention paid to it in order to make the methods reliable and 

 applicable to every varying condition. The general method is 

 to take a definite amount of the liquid, e.g. 100 c.c. (this will 

 be smaller the higher the alcohol content of the liquid), dilute 

 to a definite volume (150 c.c.) and then distill off about two 

 thirds (100 c.c). The distillate contains the entire amount of 

 alcohol present in the liquid and, in case necessary precautions 

 have been taken, contains only water in addition. Mixtures of 

 pure water and alcohol possess a definite specific gravity for 

 each variation in concentration (see Table I), so that the deter- 

 mination of the specific gravity of the distillate defines the exact 



