Feast-won, fast-lost, one cloud of winter showers.
These _flies_ are couched.
While climate points out the most suitable articles of food, it exercises
a singular influence over their qualities and properties, more especially
in vegetable substances. We find plants which are poisonous in some
countries, edible and wholesome in others. Next to climate, culture and
soil modify plants to a singular degree: flowers which yield a powerful
perfume in some latitudes, are inodorous in others; and, according to
climate, their aroma is pleasant or distressing. A striking proof of this
fact can be adduced from the well-known effects of perfumes in Rome; where
the inhabitants, especially females, cannot support the scent even of the
rose, which has been known to produce syncope, illustrating the poet's
line to
Die of a rose in aromatic pain.
This variety in the action of vegetable substances is more particularly
observable in such as are considered medicinal. Opium, narcotics, and
various drugs, are more powerful in warm climates than in northern
regions. The Italian physicians express astonishment at the comparatively
large doses prescribed by our practitioners.
Cultivation brings forth singular intermediate productions; and by its
magic power we have seen the coriaceous and bitter almond transformed into
the luscious peach, the sloe converted into the delicious plum, and the
common crab transformed into the golden pippin. The same facts are
observed in vegetables; the celery sprung from the nauseous and bitter
_apium graveolens_, and the colewort, is metamorphosed into the cabbage
and the cauliflower. All cruciform plants degenerate within the tropics,
but acquire increased energies in cold countries.
Recent experiments in Germany have demonstrated that in times of scarcity,
the wood of several trees may be converted into a nutritious substance.
The fibres of the beech, birch, lime, poplar, fir, and various other
trees, when dried, ground, and sifted into an impalpable powder,
constitute a very palatable article of food. If cold water be poured on
this ligneous flour, enclosed in a linen bag, it becomes milky, and
considerable pressure and kneading is required to express the amylaceous
or starchy part of it. Professor Von Buch, in his travels through Norway
and Lapland, has fully described the Norwegian _barke brod_. We find the
savages scattered along the coast of the great austral continent mixing up
a paste of the bark of the gum-tree with the ants and the other insects,
with their larvae, which they find in it. Ground dried fish and fish-bones
have from time immemorial been converted into bread; Arrianus tells us
that Nearchus found several nations on the shores of the Red Sea living
upon a bread of this description.
It is thus evident that all substances from the animal and vegetable
kingdom appear to afford more or less nutriment, provided that they
contain no elements unlike the animal matter of the being they are
intended to nourish. All others are either medicinal or poisonous. Food
may be considered nourishing in the ratio of its easy digestion or
solution. Magendie attributes the nutritious principle to the greater or
lesser proportion of nitrogen or azote. According to his view of the
subject, the substances that contain little or no nitrogen are the
saccharine and acid fruits, oils, fats, butter, mucilaginous vegetables,
refined sugar, starch, gum, vegetable mucus, and vegetable gelatin. The
different kinds of corn, rice and potatoes, are elements of the same kind.
The azotical aliments, on the contrary, are vegetable albumen, gluten, and
those principles which are met with in the seeds, stems and leaves of
grasses and herbs, the seeds of leguminous plants, such as peas and
beans, and most animal substances, with the exception of fat.
To this doctrine, it was objected, that animals who feed upon substances
containing little nitrogen, and the field negroes, who consume large
quantities of sugar, might be adduced as an exception. Magendie replies,
that almost all the vegetables consumed by man and animals contain more or
less nitrogen--that this element enters in large quantity in the
composition of impure sugar--and lastly, that the nations whose principal
food consists in rice, maize, or potatoes, consume at the same time milk
and cheese.
To support his theory, this physiologist had recourse to various curious
experiments on dogs, whom he fed with substances which contained no
nitrogen. During the first seven or eight days, the animals were brisk and
active, and took their food and drink as usual. In the course of the
second week they began to get thin, although their appetite continued
good, and they took daily between six and eight ounces of sugar. The
emaciation increased during the third week; they became feeble, lost their
appetite and activity, and at the same time ulcers appeared in the cornea
of their eyes. The animals still continued to eat three or four ounces of
sugar daily, but, nevertheless, became at length so feeble as to be
incapable of motion, and died on a day varying from the 31st to the 34th:
and it must be recollected that dogs will live the same length of time
without any food.
The same were the results where dogs were fed upon gum, and butter; when
they were fed with olive oil and water the phenomena were the same, with
the exception of ulceration of the cornea.
In Denmark, a diet of bread and water for a month is considered equivalent
to the punishment of death. Dr. Stark died in consequence of experiments
which he instituted on himself to ascertain the effects of a sugar diet.
Muller has justly observed that these experiments of Magendie have thrown
considerable light on the causes and the mode of treatment of the gout and
calculous disorders. The subjects of these diseases are generally persons
who live well and eat largely of animal food; most urinary calculi,
gravelly deposits, the gouty concretions, and the perspiration of gouty
persons, contain an abundance of uric acid, a substance in which nitrogen
is contained in a large proportion. Thus, by diminishing the proportion of
azotical substance in the food, the gout and gravelly deposits may be
prevented.
The experiments of Tiedemann and Gmelin have confirmed those of Magendie,
whose curious observations on the necessity of varying diet I shall
transcribe.
1. A dog fed on white bread, wheat, and water, did not live more than
fifty days.