build his shell: probably he could manage
as well with a phosphate or some other form;
and, although we can speak of the earth-
eating Otomacs, and clay-eating negroes,
we recognise in them only morbid and
unnatural feeders. We cannot, for example,
so symbolise natural characteristics as to
show a special fondness of the Germans
for food abounding in lead; of the French
for viands rich in quicksilver; or of the
Americans of a diet particularly calculated
to produce the "almighty dollar."  We
can only affirm generally, that we are all
more or less men of metal; that in all our
food we imbibe mineral matter; and that our
frame is loaded with earth.

The minerals that we eat should be regarded
from a double point of view; they should be
subdivided into those which are necessary
ingredients of the food, and invariable
elements of the body; and those which, not
being strictly necessary, are occasionally or
even frequently found in the analysis of the
organic structure. We might add the names
of many minerals used in medicines
voluntarily and of our own knowledge; or in food
involuntarily, and by way of adulteration.
Their name is legion. There would yet
remain the enumeration of minerals which
have been used by fashionable ladies, as beauty
draughts (such as antimony among the ladies
of Paris at the present day), or by others in
lower grade for like purpose, and the list
would include arsenic. For, strange as it
may appear to thinking sober men, most of
the drugs which have been employed for these
light and frivolous ends have been of poisonous
nature; as if the fair sex loved, from the
nettle Danger, to pluck the flower Beauty.
Here we should see that, at one time or
other, mankind consumed as edible or
potable matters, nearly all the minerals of
which the dust of the earth is made up. But
strike out all chance ingredients, disregard
that share of earth which fashion, fraud, or
physic forces down our throats, there yet
remain, as inevitable elements of our food,
and of our frames, phosphorus, sulphur, iron,
sodium, (the base of soda and of salt); potassium,
(base of potash); silicon, (base of flint);
calcium, (the base of lime); magnesium, (the
base of magnesia). There is a great deal to
digest in that list.

If it be a novel, it is also a startling
reflection that ingredients so combustible as
phosphorus and sulphur form ever-present
constituents of the human frame. But no other
of the inorganic substances included in our
list possesses so wide a range of organic being
as these highly inflammable materials. They
appear to be essential to the constitution of
every fibre of muscle, of every globule of
blood, of every cell of the brain and nerve
tissues. They are organised in our flesh, and
they circulate in our arteries; they are
consumed in the changes which accompany the
process of thought.

What is the ordained purpose of their
presence? Physiology mutters an imperfect
answer. We catch a glimpse of a relation to the
principal processes of growth in the large and
varying proportion found in the earliest forms
and stages of life. In the egg, proverbially so
full of meat and mystery, there is a large
proportion of phosphorus; which appears, according
to the experiments of a celebrated
physiologist, unaccountably to increase, as the
Promethean spark of life begins to glow with
a steadier and more fervent heat. The
incorporation of phosphorus with the nerve-tissues
affords a hint in a new direction. There is
no question that mental exertion is
accompanied by proportionate waste of the
substance of the brain, the instrument and engine
of thought; just as every other exertion of
force is accompanied by chemical transmutation
of matter. With this goes, hand in hand,
the consumption of phosphorus; which is an
incorporate part of the brain. The fiery
ragings of the madman, and the deep
meditations of the scholar, are accompanied, as
Dr. Bence Jones has shown, by a greater waste
of the phosphates than the expenditure of
them that goes on in ordinary or more placid
beings. The reflection is strange and
whimsical, that the most luminous coruscations of
thought have their source in a brain rich in
phosphorised fats; and that the thoughts that
breathe and words that burn, have been
really cradled from their birth in dormant
fire.

Of all the minerals that we eat, none can
claim so high a place in science, history, and
literature, as common salt. The only mineral
which we habitually consume in its raw state;
which is universally found in our food and
in our frame: which is eagerly consumed by
all nations, and in all ages: enthusiastically
lauded; blindly assailed: which is a preservative
of health, yet perhaps not unproductive
of disease: held sacred in every religion:
potent over life before man existed: as
potent, and more honoured, since man was
created.

It was in those petrified leaves which now
display, in stony characters, the recorded
history of earliest geologic ages, that the first
lines of the Biography of Salt were written.
For, many thousand years before man was
created, the toleration of salt was the tenure
by which plants and animals held their
existence. The earth was covered with salt
waters, and the air was impregnated with salt
vapours. The endurance of salt was the law
and condition of the existence of every living
thing. Plants and animals, strange forms
and monstrous, all had to swallow their
dose of salt. A ridiculous image presents
itself to our mind of a squeamish plesiosaurus,
or a fastidious dinotherium pulling a long
face over the nauseous mouthful. But there
was no help; they must thrive on it, or
perish by it: it was their daily food.  And,