The foundations of nutrition / by Mary Swartz Rose.

  • Rose, Mary Swartz, 1874-1941.
Date:
1938
Catalogue details

Licence: In copyright

Credit: The foundations of nutrition / by Mary Swartz Rose. Source: Wellcome Collection.

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    that he devise a respiration apparatus which would accom- modate a fairly large dog. Pettenkofer aspired to work with men, however, so he constructed (1862) an air tight chamber as large as the stateroom of a steamer, in which a man could live with comfort. It was ventilated by means of pumps which drew air from the outside. The air was aspirated through the chamber, and at the point of exit samples were measured, after having been passed through suitable solutions for the removal of carbon dioxide and water. These two men, Voit and Pettenkofer, working together with this apparatus established many points hitherto unin- vestigated or obscure. Rubner, later one of the masters of the science of nutrition, found while working as a pupil in Voit’s laboratory that the energy values to the body of starch and fat were equal to the heat produced by burning them in a special apparatus for heat determinations, called a calorimeter; but that the energy value of protein was dif- ferent, since it could not be as completely burned in the body as it could in the calorimeter. The values which Rubner 1 es- tablished for protein, fat, and carbohydrate are still current, although figures derived by Atwater 2 from studies upon hu- man beings seem more suitable for calculations such as are indicated in this book. The Law of Conservation of Energy in the Animal World Rubner became professor of physiology at Marburg and in 1892 in his own laboratory evolved a calorimeter large enough for a dog, which very accurately measured the heat production of the animal. This was connected with a Petten- kofer-Voit respiration apparatus, and the heat measured by the calorimeter exactly corresponded (within one per cent) to the heat calculated from the measurement of the oxygen intake, carbon dioxide output, and losses of energy-bearing 1 One gram of protein, 4.1 calories; one gram of fat, 9.3 calories; one gram of carbo- hydrate, 4.1 calories. 2 One gram of protein, 4 calories; one gram of fat, 9 calories; one gram of carbohydrate, 4 calories.