Fruits after being saturated with sugar are also preserved and kept dry. In Case 15 preserved fruits of various kinds are exhibited by Messrs. Fortnum and Mason. It is in this way that fruits are brought to this country which otherwise would not be seen on account of their perishing nature.
Treacle or Molasses is the uncrystallized portion of sugar which is separated by draining from the brown sugar.
Grape Sugar or Glucose is found in the fruits of plants, and is especially abundant in the grape. Grapes, when dried, are eaten on account of the glucose they contain. They are known in the shops under the name of “plums,” “raisins,” and “currants.” The latter word is a corruption of Corinth, the small grape yielding this, being cultivated in the vicinity of Corinth, on the classic soil of Greece.
Dried fruits of the grape-vine, presented by Messrs. Fortnum and Mason, Piccadilly, are exhibited in Case 14.
Honey, which is the stored food of the bee, contains both crystallizable and uncrystallizable grape sugar. The crystals of the former may be easily detected by the aid of a low power of the microscope. Samples of British honey, and honey from France, Russia, and other countries, may be seen in Cases 18.
Substances resembling Sugar, such as dextrin, gum, liquorice, manna, &c., are exhibited in Case 107. Among plants yielding sugar may be noted the Chinese sugar millet (Case 17), sweet potato (Case 8), turnips (Case 11), carrots (Case 11), and Jerusalem artichoke (Case 12), the analyses of which are exhibited.
Fat and Oil.
Under the names of oil, butter, fat, lard, suet, and grease, a substance is used largely as an article of food, which differs from starch and sugar in the absence of oxygen gas. The composition of these oleaginous substances may be represented as follows:—Carbon 11 parts; hydrogen 10 parts; oxygen 1 part.
Oil differs from the other carbonaceous substances in food in not only supplying materials for maintaining animal heat, but in forming a part of the tissues of the body called fat. The quantity consumed in animal food is very large, constituting frequently more than half of the bulk of the food consumed. It is also found very generally present in the vegetable substances used as food. Although essential as an article of diet in certain quantities, oil is less digestible than other kinds of food, and those foods which contain it in large quantities are generally indigestible. The principal source of oil used as food from the vegetable kingdom is the Olive. This plant is cultivated in the south of Europe. The part of the plant which contains the oil is the fruit. The seeds of most plants contain oil in addition to starch and other principles. Many seeds are used for obtaining oil for various purposes in the arts, as the poppy, rape, mustard, hemp, and flax seeds. In Case 20 is a collection of nuts and seeds containing oil commonly eaten as food. Case 21 contains the analysis of the coco-nut; and in the same Case that of an African bread called “Dika bread,” both of which illustrate food products containing an abundance of oil. The cocoa, or chocolate plant, is one of the most remarkable vegetable productions yielding oil, the seeds giving nearly 50 per cent. of a hard oil, or butter. See Case 53.