e has definite physical properties, as
crystalline structure, and forms chemical and mechanical combinations
with acid, alkaline, and other substances; it also unites with water,
and when heated undergoes changes in structural composition. The
presence of small amounts of acid substances, or variations in the
concentration of the sugar solution, materially affect the mechanical
relation of the sugar particles to each other, and their
crystallization. Usually crystallization takes place when there is less
than 25 per cent of water present. The form, size, and arrangement of
the crystals are influenced by agitation during cooling. To secure
desired results, often small quantities of various other substances are
employed for their mechanical action. Glucose is frequently used, and is
said to be necessary for the production of some kinds of candy.

Candies are colored with various dyes and pigments, many of which are
harmless, although some are injurious. Coal tar dyes are frequently
employed for this purpose. Objection has generally been urged against
their use, as it is believed many of them are injurious to health. It
cannot be said, however, that all are poisonous, as some are known to be
harmless. The use of a few coal tar dyes is allowed by the United States
government. Mineral colors are now rarely, if ever, used.

Impure candies result from objectionable ingredients, as starch,
paraffin, and large amounts of injurious coloring substances. Coal tar
coloring materials are identified in the way described in Experiment No.
13. Confectionery, when properly prepared and unadulterated, has the
same nutritive value as sugar and the other ingredients, and is entitled
to a place in the dietary for the production of heat and energy. Much
larger amounts of candies are sold and consumed during the winter than
the summer months, suggesting that in cold weather candy is most needed
in the dietary.

83. Saccharine is an artificial sweetening, five hundred times sweeter
than cane sugar. It contains in its molecule, chemically united,
benzine, sulphuric acid, and ammonia radicals. It is employed for
sweetening purposes in cases of diabetes mellitus, where physicians
advise against the use of sugar. It has no food value. A small amount is
sometimes added to canned corn and tomatoes to impart a sweet taste. The
physiological properties of saccharine have not been extensively
investigated.

CHAPTER VI

LEGUMES AND NUTS