A manual of practical hygiene for students, physicians, and health officers / By Charles Harrington.

  • Harrington, Charles, 1856-1908.
Date:
1914
Catalogue details

Licence: Public Domain Mark

Credit: A manual of practical hygiene for students, physicians, and health officers / By Charles Harrington. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

    27/992 (page 23)
    with it to 72° C, the cells swell and burst, and produce a sort of mucilage. Heated with dilute mineral acids, it is converted into dex- trose. Subjected to the action of diastase, it is converted into maltose. Starch is found almost exclusively in vegetable cells. It forms the chief part of the seeds of the cereals and of the dried residue of certain other vegetable products, such as potatoes. A form of starch known as animal starch or glycogen is found in the liver and muscles, and also in some of the moUusca. Dextrin is an artificial product formed from starch by the action of ferments or of dilute acids and heat. The Sugars are of vegetable and animal origin, and include the following: 1. Sucrose, cane sugar. A disaccharid. From sugar cane, sorghum, sugar maple, sugar beet, and some other vegetable sources. Insoluble in strong alcohol, does not reduce copper; not directly fermentable. Boiled with dilute acids, is converted to invert sugar, a mixture of dextrose and Isevulose. 2. Dextrose, glucose, grape sugar. A monosaccharid. Found in many fruits and flowers. Formed from cane sugar, maltose, starch, and dextrin by boiling with dilute acids. In the presence of decom- posing proteids, splits into two molecules of lactic acid. Fermented with yeast, splits into alcohol and carbonic acid. .3. Maltose, malt sugar. A disaccharid. (Two molecules of dex- trose.) Formed from starch by the action of diastase. ■i. Lffivulose, fruit sugar. A monosaccharid. Found in honey and various fruits. Rotates the ray of polarized light to the left. Does not form crystals. Isomeric with dextrose. 5. Lactose, milk sugar. A disaccharid. (Dextrose and galactose.) Found only in milk. Behaves like dextrose. 6. Galactose. A monosaccharid. Formed from lactose by boiling with dilute mineral acids. 7. Inosite, muscle sugar, phaseomannite. Found in certain animal tissues, as the heart's muscle, and in certain plants, as peas, beans, and grapes. Has no rotatorj' power, does not reduce copper, and is not fer- mentable. It contains the benzene ring, and hence is not a true sugar. In tlio ])iT'sence of decomposing proteids, it is converted into lactic and biitvric acids. Cellulose.—Cellulose, while of value as a food for herbivora, has no nutritive value for man. It is converted to dextrose by boiling with dilute sulphuric acid. Pectin.—Pectin is a substance not uncommonly classified as a car- bohydrate. It is a^mposed of carbon, hydrogen, and oxygen, but its precise composition is imknown. It is found in various fleshy fruits and in r<x>U, and is believed to be formed frf)m ])ectose by the action of vegetable acids. It is known also as vegetable jelly. Pectose.—Pwtose is an insohible substance found in tniripc fruits and r')ots : an ejirlier stage of pectin. ThecarbolivdratcH play an ini|)ortant part in llif ni:iiMtiiiaii<e of lifat and the prfKJuction of force. They lessen the need of liit and form fatty tissue. Excessive ingestion interferes with the metamor-