This section is from the book "Meals Medicinal", by W. T. Fernie. Also available from Amazon: Meals Medicinal: With "Herbal Simples" Curative Foods From the Cook in Place of Drugs From the Chemist.
The several Spirits - Brandy, Gin, Rum, and Whisky, - (which see) are obtained by the fermentation of various saccharine substances, their alcohol, and other volatile bodies thus produced, being separated by distillation. It is to the various bye-products which make their appearance during the fermenting process that the characteristic flavour of the different spirits is due. Thus the bye-products of the fermentation of malted barley give rise to the flavour of Whisky; those of molasses to the flavour of Rum; and those of the grape to that of Brandy. By means of patent stills these bye-products can be almost entirely separated from the alcohol with which they are mixed; and the result is a nearly pure form of spirit, the origin whereof can scarcely be discriminated; for which reason it is called "Silent Spirit." By suitable "flavouring the artful manufacturer can make this the basis of almost' any spirituous drink"- (Dr. R. Hutchison). Amongst the substances commonly used for alcoholic fermentation in this country are malted, and unmalted barley, maize, rice, sugar, and molasses.
The most valuable spirit for giving to sick persons, when really needed, is Brandy, provided it be genuine, which article is rare in this country. "The greater part of it," says Dr. Hutchison, "is spuriously concocted (actually in the Cognac district of France) from "silent spirit," whilst coloured with burnt sugar, and flavoured with oenanthine, or with various essences. But such a product is entirely different from genuine Brandy, since it is quite devoid of those volatile ethers derived from wine (in the true Brandy) to which the real Cognac owes most of the beneficial results it is capable of producing in sickness. Likewise the possession of these volatile ethers in large amount is that which mainly distinguishes Brandy from Whisky; as regards alcoholic strength the two are about equal." For Sloe Gin, as a noted astringent cordial of wide repute, a certain Mr. Nathanael Gubbins, at Chichester, used to possess a priceless prescription. Annually, on October 20th, a "Sloe" Fair (as thus interpreted) is held in that venerable city. Sloe jelly and Sloe puddings are much affected by the natives.
But originally this October Fair was a "Slo" Fair (old English, sloh, to slaughter), when the beasts were sold for killing, that they might be salted down to provide meat through the winter.