The content of alcohol by which its intoxicating power is measured varies greatly in different distillates. In Ireland and Scotland whisky is usually used, at a higher proof than in the United States. The legal strength or standard for whisky in the United States is 100 proof; that is, 50 percent of ethyl alcohol by volume. This has been fixed by what is known as the Bottling in Bond Act of 1897. This act provides that distilled spirits may be bottled in bond, provided their alcoholic proof is not less than standard. The Internal Revenue law also provides that any legal contracts in distilled spirits of which whisky is a type shall be based upon the standard proof gallon. In fact the greater part of the whisky delivered to the consumers of the United States is reduced, after the tax has been paid, by the addition of pure water until the alcoholic strength is about 90 proof, or 45 percent by volume or even less. This is done by consent of the revenue officials.

1 Commercial articles.

In certain forms of adulteration, where the cheapening of the product is the principal point to be taken into consideration, the proof of alcoholic spirits is diminished, often to a very great extent, falling as low as 35 percent in some instances. In general it may be said that an ordinary good strength whisky of the United States reaches the consumer, unless it is otherwise specified by him, at a proof strength of 90, or 45 percent per volume. The adulteration of whisky with water from the temperance point of view is regarded as a distinct advantage. It is nevertheless a typical fraud.