ount of heat required to
raise the temperature of 1 kilogram of pure water 1 degree centigrade,
or about 4 pounds of water 1 degree Fahrenheit_.

~Transformation of Foods into Available Fuel.~--A comparison has been
made between the human body and steam engine, but this comparison is
not adequate, since the food does not produce heat within the body
originally, but energy of which heat is a by-product. Each food
combination has a certain amount of dormant energy within its
structure and this energy does not become active nor can it be
utilized by the body until the food, of which it is a part, is changed
within the organism to substances more nearly like its own. This
liberated active energy is then used as a motive power to carry on the
internal and external work of the body, and the heat, which is
invariably the consequence of any active energy (motion), leaves the
body as such. It will be seen, then, that the human body acts not as a
steam engine, but rather as a ~transforming machine~ by means of which
the dormant energy of the food is transformed into an active agent of
which heat is a natural result.

In the calorimeter it was found that the carbohydrates and fats burned
to the same end products, namely, carbon dioxide and water, while the
proteins, upon oxidation, produced carbon dioxide, water and nitrogen
gas. In the body it was found that the carbohydrates and the fats
acted in exactly the same manner as in the calorimeter, producing the
same end products. But this was not the case with the proteins; the
oxidation process of this chemical combination was found to be not
nearly so complete within the body as in the calorimeter, and instead
of the free nitrogen as produced in the apparatus there were urea and
other nitrogenous substances eliminated which, while combustible,
represented a less complete oxidation of the proteins.

The following table represents the amount of heat produced as the
result of a complete oxidation of the foodstuffs in the calorimeter.

TABLE[16]

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Carbohydrates 4.1 cal. per gram
Fats 9.45 cal. per gram
Protein (nitrogen x 6.25) 5.65 cal. per gram
==================================================

The loss of potential energy due to the incomplete oxidation of the
proteins in the body is approximately 1.3 calories to each gram of
protein in food; consequently in calculating