The substance called Starch is found very abundantly in the vegetable
kingdom. Its presence was at one time regarded as characteristic of
plants, but it has recently been found in animals. It occurs in the form
of irregularly-shaped granules, which vary in size from the 1/400 to the
1/2000-th of an inch in diameter. These granules are simple or compound.
They vary in shape and size in every species of plant, and are insoluble
in water, but are easily diffused through it. On being mixed with water,
and exposed to a temperature of 180°, the starch gelatinises, and, mixing
with the water, thickens it. This occurs in the cooking of starch, and
this property lies at the foundation of pudding making.
Starch is abundantly present in all the more common forms of vegetable
diet. Is exists in a state of almost absolute purity in the substances
known as arrowroot, tapioca, and sago. These substances from whatever
source obtained, contain little or no nutritious or flesh-forming food,
and, consequently, ought never to become the substantive diet of human
beings. Many plants contain so large quantities of starch, and so small
quantities of flesh-forming matter, that they ought only to be taken on
account of their starch. Such are the potato and rice, in which the
quantity of starch to flesh-forming matter is as 14 to 1, whilst in wheat
it is only as 5 to 1. Potatoes and rice, therefore, can never form the
staple article of the diet of the people of this country, who need a
large quantity of force-producing matter in order to enable them to
perform their work.
Starch is extensively used in the arts manufactures, and for domestic
purposes. It is prepared for this purpose from the potato, wheat, rice,
flour, and the coarser kinds of sago.
In Cases 6 and 16 is an extensive series of starches, sago, arrowroot,
tapioca, &c. &c., from various parts of the world.
The following table gives the quantities of Starch in 100 parts of
various kinds of food:—
Rice 74 Beans 36
Maize 60 Lentils 35
Wheat 59 Parsnips 17
Rye 51 Potatoes 15
Buckwheat 50 Mangel Wurzel 12
Bread 48 Carrots 11
Barley 48 Turnips 10
Oats 39 Cabbage 4
Peas 37