Food in health and disease / By I. Burney Yeo.

  • Yeo, I. Burney (Isaac Burney), 1835-1914.
Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: Food in health and disease / By I. Burney Yeo. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

    15/614 (page 3)
    Chap. I.] Nature and Purpose of J<ood. a.s imiHcular and in'i’Aon.s action, lieat t'onnation, nutri- tion, .secretion, assimilation, and rei)roduction. l>ut a substance in order to be suitable for food must not merely possess the elements indicated, it must also contain them in a mode or combination which enables them to be appropriated, i.e. to be digested and assimilated, by the organs of the body it is to feed. The jjlant —the grass-plant, for example —is enabled to appropriate, and therefore to use as food, the soluble mineral mattei’s of the soil in which it grows, di.s.solved in the rain-water which falls upon it, together with what it absorbs from the gases of the air. It is a characteristic of the mejnbers of the vegetable kingdom that they are able to feed on inor- iimuG substances. Animal organisms are unable to flo so; thej^ are dependent on vegetable organisms to proykle them with food that they can appropriate. The ox is enabled to appropriate, and use as food,. the gras.s that is itself fed on inorganic substances, upon which the ox cannot feed ; and from this grass it IS enabled to build up structures, and to ])erform functions of the same kind as those possessed by man himself. Yet grass, such as the ox feeds on, is not a suitable food for man, because its comjionent elements are not so arranged as to enable his organs to di^-est and assimilate them; but, on the other hand, 'the same elements having undergone some further elabora- tion, as in the ripe seed of certain species of grass, wlien fitly prepared, form one of the most useful toods that man can obtain, as the meal of wheat barley, oats, etc. ’ Thus, in considering the oriyin of food, we learn how the simplest vegetable forms grow and feed on the constituents of the atmosphere alone, the carbon and nitrogen of their tissues being derived from the carbonic acid and ammonia always present in small quantity together with aqueous vapour, in the air Ihe larger vegetable forms feed also, to some ex- tent, on the gases of the air, but they also feed largely on the organic and inorganic constituents of the soil