Potato as Food.—No doubt much of its popularity is due to its cheapness, its good keeping power, and its unobtrusive flavour. Since the potato disease it has not always been as cheap as once it was, but it still remains one of the cheapest, if not the cheapest, of foods. We have cheap corn now, and if potatoes and corn were the same price per pound, corn would be the cheaper of the two. For potatoes are very watery. Three-quarters of the weight of every potato is water, and of the remaining quarter half is starch, there being much less of flesh-forming material than in many other cheap foods. If a man had to live on potatoes alone, he must eat many pounds weight daily in order to obtain flesh-formers enough to do even moderate work. The Irish, who do live on potatoes, add buttermilk to supply what is wanting, and even so consume immense quantities of vegetables. Potato, however, besides starch and water, contains much ash or salt, and is for that reason an excellent anti-scorbutic. It is a strange fact that many English people, from one week's end to another, eat no vegetable except potato, an exotic, acclimatised here at the cost of much pains and perseverance.
The potato belongs to the order Solanaceae, to which also belong some of the deadliest poisons we possess, and also contains a poisonous principle known as solanine. Potatoes that have been frozen rapidly decompose, because, owing to the freezing of the water that they contain, the cells are burst and broken. They also deteriorate if they are allowed to sprout. Some or all of the starch is changed to dextrine, a gummy substance with a sweetish taste, which no longer assumes a mealy appearance on boiling as does a starchy potato. The waste in boiling is much less if the tubers are boiled in their skins, which are of a cork-like substance impervious to water. There is also considerable waste in peeling potatoes, owing to the fact that the least watery and most albuminous part of the tubers lies immediately under the skin. It is said that one seventh of every potato is wasted by the common method of cooking.
Potato starch is largely used to adulterate other farinaceous preparations, as it is the cheapest form of starch. It is, however, stated that it turns watery sooner than other starches if allowed to stand after it is cooked.
Vegetables of the Olden Time.—Not only potatoes, but many other vegetables now common, were unknown to our forefathers even a few centuries back, and the fruits were very different to those at present produced in England. The following extract, from Professor Thorold Rogers' well-known work on the History of Prices, serves to show the then existing state of things.
"The manor house possessed a garden and orchard. But the former very deficient in vegetables. The householder of the thirteenth and fourteenth centuries grew onions and leeks, mustard, and garden or green peas. He probably possessed cabbage, though I have never