Draper — Percentage of Alcohol in Alcoholic Beverages. 377 



at its upper end is coloured blue. The fourth column, terminating 

 in yellow, represents spirit containing 90 per cent, of proof spirit, 

 the strength at which whiskey, rum, and brandy are (or are supposed 

 to be) generally sold. 



These are the standard or reference columns ; and to obtain the 

 alcoholic percentage of the liquid in any other column in terms of 

 these standards, it is only necessary to note what marginal figures 

 are intersected by a straight-edged rule laid across the upper termi- 

 nations of either red, blue, or yellow : — 



Red indicating Absolute Alcohol. 



Blue „ Proof Spirit. 



Yellow ,, Spirit of 10 Under Proof. 



For example : 100 parts of London gin are equal to 47 parts 

 absolute alcohol, 82*40 of proof spirit, and 90*64 of whiskey, brandy, 

 or rum, at 10 per cent, under proof. Therefore, by multiplying 

 any given quantity of London gin by 0*47 we obtain the alcoholic 

 equivalent of that quantity in absolute alcohol, by 0*824 in proof 

 spirit, and by 0*906 in terms of whiskey. The same method of 

 calculation is applicable throughout. 



But that the table shall be of practical use, it is necessary 

 that the volume contents of the "glasses" from which alcoholic 

 beverages are most ordinarily consumed shall be known. These 

 of course vary, but the following figures may be considered as 

 giving a close approximation to the mean contents of the " glasses " 

 and " bottles " in common use. The standard of measure employed 

 is the fluid ounce or one-twentieth part of the imperial pint. 



In order to illustrate the use of the table, a hypothetical case 

 may be taken, in which it is desired to ascertain the quantity of 

 absolute alcohol ingested by a person who in the course of a clay has 

 taken a glass of sherry, a small bottle of Lager beer, and a glass of 



2 G2 



