The philosophy of eating. By Albert J. Bellows, M.D.

GRANULES OF STARCH.

63

heat is starch, which is found in all vegetable food
except the fruits.
It exists in irregularly shaped granules, varying in
size from 2-1 — to T; of an inch in diameter, in
different species of plants, each plant furnishing its own
peculiar granules. These granules are insoluble in cold
water, but are readily diffused through it, so that by
bruising or crushing the grain or potato that contains
it, and washing in cold water, the starch is separated
from the other principles, and, being of greater specific
gravity than water, settles to the bottom of the vessel
containing it, and may thus be obtained in greater or
less amounts from all edible vegetables and grains.
On being mixed with water of a temperature of
180~, starch becomes glutinous and loses its granular character, and in this state is much used in the
arts to give firmness and inflexibility to fabrics of
clothing, &c.
Starch is turned blue by iodine, and the extent of its
presence in any grain can therefore be easily tested by
carefully slicing and soaking the grain and applying
a solution of iodine. From wheat and corn, &c., thus
treated, the drawings were made for Figs. 2, 3, 4, &c.
The nitrogenous and phosphatic principles may be delineated by other appropriate tests.
When starch is taken as an article of diet, its carbon
is burned in the lungs in contact with the oxygen of
the air, and gives out heat to warm the system, just as
the carbon of wood, uniting with the oxygen of the
air, gives out heat to warm our apartments; but before