4 Manitoba Agricultural College

and sugars) are present in proportion to form water. It is on the
vegetable kingdom we depend for these foods. Sugar is ina form with
which the digestive organs can deal more readily than with starch.
While the two substances contain the same elements, they are present
in different proportions, and the starch has to be converted into sugar
_ before it can be taken up by the blood and serve its purpose in the body.
Whatever the source of starch or sugar, whether it be the starch as
it is found in the corn or extracted and used in the form of cornstarch,
it has just as great power to provide energy for the body.

The chief objection to replacing starch by the use of sugar is that
sugar is nearly ready to be utilized as soon as it is eaten, and if par-
taken of in too great quantities may enter the blood in such large
quantities that it can not be disposed of without causing disturbances
in the digestive tract; and starch, since it has to be converted into
sugar, is changed very slowly and is in a much diluted form, so that
it can be used as soon as it is absorbed, thus preventing any cause of
immediate danger. Raw starch can be digested in the system, but
it takes much longer than when thoroughly cooked, hence the neces-
sity of thoroughly cooking starch before using it as food, to aid in the
digesting of it. In the system it is first acted upon by the saliva, an
alkaline fluid in the mouth, if it is retained in the mouth long enough
to be mixed with the saliva. It then passes into the stomach, where
digestion is retarded, since the gastric juices are acid in action. It
then passes into the intestines, where another alkaline substance acts
upon it and converts it into a substance which can be taken up by
the blood and carried to the part of the body requiring that material
for its use. Some foods which contain a relatively large amount
of starch are rice, bread, oatmeal, beans, potatoes, etc. The chief
uses of carbohydrates in the body are to supply heat and energy, but
if taken in larger quantities than required for this purpose they may
be stored in the form of fat, which can be used as a reserve supply in
case of cold, famine, or excessive exertion. It is to the use of exces-
sive quantities of starch and sugar that very stout people can usually
trace their excess of adipose tissue. It is customary to use bread at
all meals, and frequently potatoes, and since these are included in the
list of starchy foods, there is little danger of a lack of carbohydrates
in the diet. Taken with proteid foods, they aid in the digestion of
the highly concentrated foods such as cheese, eggs, meat, etc. For
this reason we have such familiar combinations as “‘ crackers and
cheese.”’ There is a possibility of partaking of a meal composed
almost entirely of carbohydrates, and if it has followed one rich in
proteid, it is not objectionable, since it balances up the principles
necessary to meet the demands of the body for the day, and thus
prevents the overtaxing of the system.

Cellulose is composed of the same elements as starch and is chemi-
cally the same. It is the woody fibre or the framework of the vege-
table which holds the other substances together. When young, the