The question is pertinently raised here as to what these congeneric principles are in a whisky. Chemists have discovered in whisky from 20 to 40 different substances, and all of these are necessary to make a real whisky, even though they be present, as they are usually, in minute quantities.

In this work it will be necessary only to mention the principal congeneric products which are found in a whisky. The reader may consult technical and chemical works for details.

In addition to ethyl alcohol, which is the principle volatile constituent of whisky, there are found the following important constituents: