Vegetable substances used for the food of man / [Edwin Lankester. Revised and partly rewritten].

  • Edwin Lankester
Date:
1846
Catalogue details

Licence: Public Domain Mark

Credit: Vegetable substances used for the food of man / [Edwin Lankester. Revised and partly rewritten]. Source: Wellcome Collection.

    18/518 page 12
    CHAPTER 1. GENERAL CONSIDERATIONS ON THE NATURE OF VEGETABLE FOOD. Before entering on the consideration of particular plants yielding the food of man, we shall endeavour to give our readers some idea of the ultimate composition of the parts of plants used as food, and of the functions they perform in the animal system. When the chemist analyses the structure of plants or animals, he finds that the elementary matters of which they are com- posed are nearly all identical, there being only a few elements which have been found exclusively in either the animal or vegetable kingdom. Chemists enumerate fifty-five elements, not more tlnm a third of which have been found present in animals and plants, and four only of these are found constantly jiresent in organic bodies. These four arc carbon, hydrogen, oxygen, and nitrogen, and from their constituting so largo a proportion of organised bodies, they are sometimes called organic elc- rncnls. However varied may be the forms, colours, smell, and taste of the vegetable kingdom, or diversified the structure or I’unctions of the animal kingdom, their great bulk is composed of these four elements. As instances, however, of tlic jircsence of other elements, wc mav mention that the oxides of potassium and sodium (potash and soda) are frequently jirescnt in jilants, and that jihosphato of lime constitutes a very important ingredient in the bones of all animals. Although the inorganic elements, as those bodies which do not universally enter into the structure of plants and animals arc called, do not exist in large quantities, they nevertheless perform an ini])ortant part in the functions of the tissues, into the
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