Page:The American Cyclopædia (1879) Volume XIII.djvu/791

 POTATO without freezing. The value of potatoes as food depends upon the amount of starch they contain, -and this is in direct relation to their specific gravity; according to Pohl, those of sp. gr. 1-090 contain 16-38 parts of starch in 100, while those of sp. gr. 1-123 yield 24-14. The amount of starch varies with the season, unripe tubers containing scarcely two thirds as much as those thoroughly mature ; and again in spring, when vegetation begins, the starch perceptibly diminishes. An average of 19 analyses by Grouven of various kinds of pota- toes, freshly dug, gave water 76-00, albumi- noids 2-80, starch 15-24, besides cellulose, gum, and other principles, and 0-95 of ash. The amount of ash varies from 0-88 to 1-30 in 100 parts, and this is more than half potash. As an article of food potatoes are deficient in albu- minoids and phosphates, and among the Irish peasantry, where they form a large portion of the diet, the custom of eating them with but- termilk or skim milk is founded upon correct principles, as these supply the elements in which the potato is deficient. According to Smith (" Foods " in the " International Scien- tific Series "), " more than 2 Ibs. of potato are required to equal 1 Ib. of bread in carbon, and more than 3 Ibs. in nitrogen." Tastes in regard to the quality of potatoes and meth- ods of cooking them vary greatly; the general preference is for a dry floury ball of starch, with an absence of all flavor. The Irish boil them only so much as to leave the centre still a lit- tle hard, or " with a bone in it." Although in some parts of France potatoes are almost as largely consumed as in Ireland, the French gen- erally do not regard them as essential to a meal, and rarely eat them plain boiled, but dressed in some of the many forms peculiar to the coun- try; the German finds them most acceptable as a salad. Potatoes are used to some extent as a food for domestic animals, especially for swine ; fed occasionally to horses, they are an excellent corrective of the digestion. Their antiscorbutic property renders them valuable on sea voyages, and they form a part of the dietary in prisons on this account. During the mining excitement in California, where men lived almost exclusively upon salt meat and fine flour, land scurvy was very prevalent, but yielded to potatoes, which met with a ready sale at $1 each, to be eaten raw. A thin slice of the potato examined with the microscope shows very large and thin cells filled with starch grains, which are about 12 in number in each cell, much larger than any others of the ordinary forms of starch, and distinctly marked with concentric lines. Potatoes are largely used in the manufacture of starch (see STARCH), and in Europe are distilled to produce spirit. According to the census of 1870, the total pro- duction of potatoes in the United States was 143,337,473 bushels, of which New York pro- duced 28,547,593 bushels, Pennsylvania 12,- 889,367, Ohio, 11,192,814, Illinois 10,944,790, Michigan 10,318,799, Maine 7,771,009, Wiscon- POTATO (SWEET) 767 ^ 6 46 > 129, Iowa 5,914,320, Indiana 5,399 - ?Jn'x7 eri ?r 0nt 5 > 15T > 428 > New Jersey 4,705!- 439, New Hampshire4,515,419, Missouri 4 238 - 361, and Massachusetts 3,025,446 POTATO, Sweet, a plant of the convolvulus family, variously classed by botanists as batatas edulis, convolvulus batatas, and preferably ipo- meea batatas. It has a large edible root, creep- ing smooth stems, and very variable leaves- these are sometimes heart-shaped, often hal- berd-shaped or angled, and it is not rare to find them deeply lobed; the flower is much like that of the common morning-glory, not quite so much spreading, and of a rosy-purple color in the throat with white on the margin; it rarely produces flowers in the northern states. Ihere is much doubt concerning the native country of the sweet potato, and there is strong evidence in favor of both its American and East Indian origin. It has not been found in the wild state in either country. Sweet pota- Sweet Potato (Ipomsea batatas). toes were among the presents Columbus took to Isabella on his return from the new world, and the plant was in general cultivation in Spain in the middle of the 16th century; on the other hand, it is said to have been in culti- vation in China and other parts of the East in very early times. It is believed that this is the potato of Shakespeare and other early English authors, and was known in Europe before the introduction of the white potato. The roots vary much in size and color, and there are sev- eral varieties in cultivation, the two most suc- cessful in northern localities being the Nanse- mond and Southern Queen, while in the south- ern states a variety known as the yam potato s regarded as one of the best. Not many years ago no one thought of cultivating the sweet potato north of Virginia, but it is now regard- id as a profitable and important crop in Ohio, [llinois, and other western states, and in New- Jersey in the east, and will succeed fairly in