This section is from the book "Practical Dietetics With Special Reference To Diet In Disease", by William Gilman Thompson. Also available from Amazon: Practical Dietetics with Special Reference to Diet in Disease.
Strong spirits, such as rum, whisky, brandy, and gin, are the worst forms of alcohol for daily drinking, and liquors of this class are responsible for nine tenths of the evils of inebriety. In localities where their consumption has been brought into competition with or has been superseded by that of beer, drunkenness has often diminished. As the system acquires toleration for the stronger forms of liquor, it is found that its desired effects can only be obtained by constantly increasing the strength or the frequency of the drinks, and meanwhile the alcohol absorbed is gradually converting the different tissues of the body into pathological specimens.
The drinking of new and raw liquors is particularly injurious, for time mellows them somewhat and reduces the quantity of their most hurtful ingredient - fusel oil - while their flavour improves. The difference in taste of liquors depends upon the substances from which they are made much more than upon any skill in their manufacture or modifications in their fermentation, circumstances which so materially affect wines. The taste varies with the relative quantity present of aldehyde, compound ether, higher alcohol (fusel oil), and volatile bases.
Brandy and other strong spirits are distilled from a variety of carbohydrate foods: such are potatoes, corn, rye (whisky), beets, rice (arrack and sake), molasses (rum), crushed grapes, apples (applejack), peaches, plums, cherries (Kirsch), and other fruits. These spirits contain from 45 to 60 per cent of alcohol, besides cane sugar and extractives.
French Cognac is a strong, pure brandy, distilled either from wine, or directly from crushed grapes. It may be coloured by caramel. Common brandy is distilled from wine.