be as
fresh as possible, or, if this is not feasible, they should be
preserved in such a way as to prevent their becoming rancid--a
condition which is the result of the formation of fatty acids,
lending a peculiarly unpleasant odor and taste, and producing a
decided decrease in food-value. This alteration may be largely
prevented by keeping fats in a refrigerator at a low temperature,
and may also be greatly retarded by the addition of salt. In this
country butter is usually treated with a very considerable amount
of salt, but in Europe it is universally served fresh. Within
recent years facts have been established that show that Americans
use an excessive amount of this substance--possibly causing disease
in some cases; and doubtless we would be better off if we were to
follow the European practice.

Oily substances when in good condition are certainly of high value
as foods, but should be taken more or less with an eye to the
climate, and to the season of the year. When placed on cold bread
and eaten along with it they are extremely palatable, and may be
taken in reasonable amounts with decided benefit to the whole body.
In temperate climates it is generally estimated that about three
ounces is a desirable amount for the average adult. In this
connection it may not be out of place to mention that the various
preparations of cod-liver oil, advertised so freely in the lay
press, in some instances actually do not contain a single particle
of the substance that they are supposed to be principally composed
of; and it may be further stated that there is no good reason to
believe that bulk for bulk oils of this kind are in any way
superior to those fats commonly eaten. The writer often recalls the
saying of a very wise old physician of his acquaintance that
"cod-liver oil is nearly as good as butter."

_Sugars._--This term includes the large number of different substances of
a more or less sweetish taste that belong to the group of carbohydrates.
They are closely related to the starches, and it is generally assumed
that they play much the same part after being taken into the body. Some
of these are of animal and some of vegetable origin--but except the sugar
found in milk, the only ones commonly consumed are those derived from
cane, beets, and fruits; the sugar from the first two i