Such an apparatus is termed a double boiler. Food cooked in its own
juices in a covered dish in a hot oven, is sometimes spoken of as being
_steamed_ or _smothered_.

_Stewing_ is the prolonged cooking of food in a small quantity of
liquid, the temperature of which is just below the boiling point.
Stewing should not be confounded with simmering, which is slow, steady
boiling. The proper temperature for stewing is most easily secured by
the use of the double boiler. The water in the outer vessel boils, while
that in the inner vessel does not, being kept a little below the
temperature of the water from which its heat is obtained, by the
constant evaporation at a temperature a little below the boiling point.

_Frying_, which is the cooking of food in hot fat, is a method not to be
recommended--Unlike all the other food elements, fat is rendered less
digestible by cooking. Doubtless it is for this reason that nature has
provided those foods which require the most prolonged cooking to fit
them for use with only a small proportion of fat, and it would seem to
indicate that any food to be subjected to a high degree of heat should
not be mixed and compounded largely of fats. The ordinary way of frying,
which the French call _sauteing_, is by the use of only a little fat in
a shallow pan, into which the food is put and cooked first on one side
and then the other. Scarcely anything could be more unwholesome than
food prepared in this manner. A morsel of food encrusted with fat
remains undigested in the stomach because fat is not acted upon by the
gastric juice, and its combination with the other food elements of which
the morsel is composed interferes with their digestion also. If such
foods are habitually used, digestion soon becomes slow and the gastric
juice so deficient in quantity that fermentation and putrefactive
changes are occasioned, resulting in serious disturbance of health. In