A treatise on human physiology : designed for the use of students and practitioners of medicine / by John C. Dalton.

  • John Call Dalton
Date:
1871
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on human physiology : designed for the use of students and practitioners of medicine / by John C. Dalton. Source: Wellcome Collection.

    97/768 (page 97)
    OF FOOD. 97 albuminoid substances were known as tbe nutritious or plastic ' elements. ! This distinction, however, has no real foundation. In the first place, it is not at all certain that the sugars and the oils which dis- j appear in the body are destroyed by combustion. This is merely ' an inference which has been made without any direct proof. All we know positively in regard to the matter is that these substances soon become so altered in the blood that they can no longer be recognized by their ordinary chemical properties ; but we are still ignorant of the exact nature of the transformations which they undergo. Furthermore, the difference between the sugars and the oils on the one hand, and the albuminoid substances on the other, j so far as regards their decomposition and disappearance in the body, is only a difference in time. The albuminoid substances become transformed more slowly, the sugars and the oils more rapidly. Even if it should be ascertained hereafter that the sugars ' and the oils really do not unite at all with the solid tissues, but are : entirely decomposed in the blood, this would not make them any less important as alimentary substances, since the blood is as essential a part of the body as the solid tissues, and its nutrition must be provided for equally with theirs. It is evident, therefore, that no single proximate principle, nor even any one class of them alone, can be sufficient for the nutrition of the body; but that the food, to be nourishing, must contain I substances belonging to all the different groups of proximate prin- j ciples. The albuminoid substances are first in importance because ! they constitute the largest part of the entire mass of the body; and j exhaustion therefore follows more rapidly when they are withheld j than when the animal is deprived of other kinds of alimentary ; matter. But starchy and oleaginous substances are also requisite ; j and the body feels the want of them sooner or later, though it may j be plentifully supplied with albumen and fibrin. Finally, the in- - organic saline matters, though in smaller quantity, are also neces- ; sary to the continuous maintenance of life. In order that the animal tissues and fluids remain in a healthy condition and take ; their proper part in the functions of life, they must be supplied \ with all the ingredients necessary to their constitution; and a man j may be starved to death at last by depriving him of chloride of ; sodium or phosphate of lime just as surely, though not so rapidly, ' as if he were deprived of albumen or oil. ; In the different kinds of food, accordingly, which have been ] j