se and its proper combination with other
foods, particularly with those rich in the nitrogenous compounds or
proteids. Sugar alone is incapable of sustaining life, but combined with
other foods is a valuable nutrient. The amount which can be
advantageously used depends largely upon the individual. Ordinarily
three to five ounces per day is sufficient, although some persons cannot
safely consume as much as this. In the case of diabetes mellitus, the
amount of sugar in the ration must be materially reduced. Persons in
normal health and engaged in outdoor work can use sugar to
advantage.[29] Many of the "harvest drinks," made largely from molasses
with a little ginger, and used extensively in some localities, are not
without merit, as they contain an appreciable amount of nutrients. Milk
contains more sugar as lactose or milk sugar than any other nutrient.

[Illustration: FIG. 17.--NUTRIENTS OF A RATION WITHOUT SUGAR.

The hacket parts represent the proportion of nutrients not digested.]

The craving for sugar by growing children and athletes is natural.
Sugar, however, is often injudiciously used, and a perverted taste may
be established which can be satisfied only by excessive amounts. This
results in impaired digestion and malnutrition.

76. Maple Sugar.--Sugar obtained by evaporation from the sap of the
maple tree (_Acer saccharinum_) is identical, except for the foreign
substances which it contains, with that from the beet and sugar cane.
The mottled appearance and characteristic color and taste of maple sugar
are due to the various organic acids and other compounds present in the
maple sap and recovered in the sugar. Maple sugar, as ordinarily
prepared, has 0.4 of a per cent or more of ash or mineral matter, while
refined cane sugar contains less than one tenth as much.[30] Hence, when
maple sugar is adulterated with cane and beet sugars, the ash content is
noticeably lowered, as is also the content of organic acids. It is
difficult, however, to determine with absolute certainty pure high grade
maple sugar from the impure low grade to which a small amount of
granulated sugar has been added.

77. Adulteration of Sugar.--Sugar at the present time is not
materially adulterated. Other than the substances mentioned which are
used for clarification and color, none are added during refining which
remain in the sugar in appreciable amounts. Sugar does not readily lend
itself to adulteration, as it has a definite crystal