capable of digestion. They contain hydrogen and oxygen in the proportion
to form water, the carbon alone being available to produce heat by
combustion. Starch is the most widely distributed food. It is insoluble in
water, but when cooked is readily digested and absorbed by the body.
Starch is readily converted into sugar, whether in plants or animals,
during digestion. There are many kinds of sugar, such as grape, cane and
milk sugars.

The Oils and Fats consist of the same elements as the carbohydrates,
but the hydrogen is in larger quantity than is necessary to form water,
and this surplus is available for the production of energy. During their
combustion in the body they produce nearly two-and-a-quarter times (4 :
8.9 = 2.225) as much heat as the carbohydrates; but if eaten in more than
small quantities, they are not easily digested, a portion passing away by
the intestines. The fat in the body is not solely dependent upon the
quantity consumed as food, as an animal may become quite fat on food
containing none. A moderate quantity favours digestion and the bodily
health. In cold weather more should be taken. In the Arctic regions the
Esquimaux consume enormous quantities. Nuts are generally rich in oil.
Oatmeal contains more than any of the other cereals (27 analyses gave from
8 to 12.3 per cent.)

The most esteemed and dearest oil is Almond. What is called Peach-kernel
oil (Oleum Amygdalæ Persicæ), but which in commerce includes the oil
obtained from plum and apricot stones, is almost as tasteless and useful,
whilst it is considerably cheaper. It is a very agreeable and useful food.
It is often added to, as an adulterant, or substituted for the true Almond
oil. The best qualities of Olive oil are much esteemed, though they are
not as agreeable to English taste as the oil previously mentioned. The
best qualities are termed Virgin, Extra Sublime and Sublime. Any that has