VARIETY OP FOOD NECESSARY.
333
starch, on the twenty-fourth, and another on the twenty-seventh day;
having lost during these periods from one-sixth to one half of their
weight. But a goose which was fed with boiled white of egg cut
into small pieces, although it maintained its appetite, and the food
contained nitrogen, also died on the forty-sixth day, after having lost
nearly one half of its weight. These experiments of Tiedemann
and Gmelin, like those of Magendie above detailed, would be very
conclusive if the same animals had been fed alternately on different
substances that contained no nitrogen; for the experiments of Ma¬
gendie, which follow, show that animals are frequently not able to
support a diet consisting invariably of one and the same substance,
though it contain azote. (See Londe, Froriep’s Notiz. Bd. xiii. No.
10.)
Necessity of variety in diet.—Magendie’s further experiments
on the nutritious property of different substances afforded the fol¬
lowing facts:—1. A dog fed on white bread, wheat and water, did
not live more than fifty days. 2. Another dog, on the contrary,
which was kept on brown soldier’s bread, did not suffer. 3. Rabbits
and Guinea-pigs fed on any one of the following substances,—
wheat, oats, barley, cabbage, or carrots,—died with all the signs of
inanition in fifteen days; while, if the same substances were given
simultaneously, or in succession, the animals suffered no ill effect.
4. An ass fed on dry rice, and afterwards on boiled rice, lived only
fifteen days. A cock, on the contrary, was fed with boiled rice for
several months with no ill consequence. 5. Dogs fed with cheese
alone, or with hard eggs, lived for a long time, but they became
feeble and thin, and lost their hair. 6. Rodent animals will live a
very long time on muscular substance. 7. After an animal has been
fed for a long period on one kind of aliment, which, if continued,
would not alone support life, he will not be saved by his customary
food being given to him: he will eat eagerly, but he will die as soon
as if he had continued to be restricted to the one article of food which
was first given. The conclusion to be deduced from the above facts
is, that variety of the kinds of aliment is an important circumstance
to be attended to in the preservation of health. The statement of
M. Magendie, that for the nutrition of animals variety of diet is ne¬
cessary, and that restriction to one kind of food induces emaciation
and death, has been fully confirmed by a comparative experiment
instituted on three rabbits by M. E. Burdach. (Froriep’s Not. Oct.
1839, p. 43.)
Dr. Prout (on the Nature and Treatment of Stomach and Uri¬
nary Diseases,) reduces all the articles of nourishment, among the
higher animals, to four great classes or groups: 1, the aqueous; 2, the
saccharine, comprehending sugar, starch, gum, &c.; 3, the oily, in¬
cluding oils and fats; and 4, the albuminous,—the last the proximate
principle of animals, and a modification of which is vegetable gluten.
After a short account of each of these classes, he makes the following
summary of the subject:—
“Such are the four great alimentary principles, by which all the
higher animals are nourished, and of which their bodies are essen-