tamine to the action of alkalies; the
sensitiveness of the "C" vitamine to heat, alkali and acid, moreover
the limitation of its presence chiefly to the fresh fruits and plant
juices,--all point to the need of special care in the selection of the
food materials and of the manner in which these materials are prepared
for consumption.

SUMMARY

In the descriptions just given of the various foodstuffs, especially
in regard to their function in the body, it is readily seen that no
one foodstuff is used to the exclusion of another. It is further seen
that in the upkeep of the body, which includes not only the building
and repairing of its tissues, but the running of the engine and
maintaining of its normal temperature, the organism uses each and all
of the organic food substances for the production of heat.
Furthermore, while the tissues are chiefly built from protein
material, and physiology teaches that protein can be built only from
other protein, these tissues contain a certain amount of carbohydrate,
fat, mineral salts, and water; this furnishes distinct evidence that
the building of the cells and tissues of the body cannot be
accomplished by means of protein alone, but by the judicious balancing
of all the foodstuffs in the dietary.

Science has gone even further than this, as has just been
demonstrated, and has proven that without the substances known as
vitamines the normal growth and development in the young would be
arrested, and that the maintenance of the adult body would be
impaired. It has also proven that certain diseases owe their
development to deficiencies in the vitamine supply to the body.

PROBLEMS

(a) Outline briefly what is believed to be the essentials of an
adequate dietary.

(b) List the fuel foods and show their most economical source.

(c) List the best sources of the complete proteins.

(d) Show how the incomplete protein foods may be made adequate for
growth.

FOOTNOTES:

[1] One quart of milk contains more calcium than a quart of clear
saturated solution of lime water.

[2] For complete list, see Eddy's Table, in Appendix.

[3] "Chemistry of Food and Nutrition" (revised edition), by Sherman.

[4] Scientists are proving the need for certain vitamine factors in
the diet in order that the growth and development of young tissues and
the repair of adult tissues may proceed. The part played by these
substances will be discussed later.

[5] "Chemistry of Food and Nutrition"