Treatise on human physiology : For the use of students & practitioners of medicine / By Henry C. Chapman. Illustrated with 595 engravings.

  • Chapman, Henry C. (Henry Cadwalader), 1845-1909.
Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: Treatise on human physiology : For the use of students & practitioners of medicine / By Henry C. Chapman. Illustrated with 595 engravings. 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.

    79/934 (page 73)
    On the otlier hand, if the food consists of meat ah)ne, tlicn in order to obtain the necessary 2S1 grammes of carbon as much as 2981 grammes of meat would have to be eaten, the economy receiv- ing then three o-rannnes of carbon to one of nitrogen, the amount of carbon being tlien one-fifth of what it ought to be, relatively to the nitrogen, and the latter in amount absolutely five times too great. If, however, bread and meat be eaten in the proportions given in the table, then the economy will receive for about sixteen grammes of carbon one gramme of nitrogen, the ratio differing a little from that of the excreta, as might be expected, the food of the man con- sisting, as we shall see, of other articles as well as of bread and meat. In the latter case when the carbon and nitrogen of the in- gesta and egesta balance each otlier, and, indeed, the salts and water as well, the economy is then said to be in a state of carbon and nitrogen equilibrium. It should be mentioned, in connection with the example just given of a diet restricted to meat, that, as a matter of fact, life cannot be maintained upon such a diet. As more than 2.2 kilogrammes (4.8 lbs.) of meat must be eaten and digested by a man in 24 hours in order to obtain the 280 grammes of carbon, a task is imposed upon the digestive organs tliat they cannot perform. A man soon succumbs upon a purely meat diet, drawing upon the fat of his own body to supply that which should be present in his food. Even a carnivorous animal, like a dog, whose alimentary apparatus is especially adapted to digest meat, can only be kept alive upon a purely meat diet, when fat and muscular at the begin- ning of the experiment, and when the meat eaten is equal to the -^^ or Jg of the weight of the body, a diet which increases enormously the excretion of urea, a condition far from physiological. On the other hand, if the food consists of fat alone, man or beast will live but a short time, and it is Morthy of mention that on such a diet less urea is excreted than in the starving condition, the albu- minous tissues, the source of the urea, being spared through the oxidation of the fat. If more fat, however, be taken than can be disposed of in this way, as shown by the retention of carbon in the system, then fat is stored up and the albuminous tissues destroyed. The effect of a carbohydrate diet is essentially the same as a fatty one, sugar or transformed starch being, however, more readily oxi- dized than fat, seventeen parts of sugar being equal to ten parts of fat in this respect; less urea is, therefore, excreted upon a carbo- hydrate diet than upon a fatty one. A certain amount of body fat appears to be also destroyed upon a carbohydrate diet. Of all foods, milk is the one which combines in itself to the greatest extent the proper substances in quantity and quality for the nutrition of the body, and Mere life limited to its earlv periods, it might l)e stated that milk alone would suffice for the maintenance of life ; as the child, however, develops into the adult necessity is felt for other kinds of food as well. All through life, however, milk constitutes a most important article of diet, and can be more relied upon, both in sickness and in health, than any other kind of food.