General Remarks on the Work. 



Ninety-two per cent, alcohol is the " ordinary" methylated spirits of commerce, 

 free from the mineral additions as supplied by chemists. The strength of alcohol, 

 as sent out from the distillery, varies from 88 per cent, to 92 per cent. In 

 making up percentages, therefore, it is safest to calculate on a 90 per cent, 

 strength, unless the student can obtain its specific gravity by means of the 

 hydrometer. Percentages for all ordinary purposes may be obtained by volume 

 as shown in the following table. 



To obtain any required quantity of any given percentage of alcohol from 

 the above table, take for example, required 250 cc. of 60 per cent, of alcohol, 

 how much 90 per cent, alcohol will be required. 1500 : 250 : : 100 = i66f cc. 



