The knowledge of food values and their relation to the body will be of
little use for practical purposes unless combined with the knowledge
of how the various foods should be prepared, either by cooking or in
whatever form circumstances and the material may require. The first
requisite for cooking purposes is heat; this necessitates the use of
fuel. The fuels chiefly used for household purposes are wood, coal,
kerosene oil and gas. Soft woods, such as pine or birch, are best for
kindling and for a quick fire. Hard woods, oak, ash, etc., burn more
slowly, retain the heat longer, and are better adapted for cooking
purposes.

COAL.

Coal (anthracite) is about 95 per cent. carbon. It kindles slowly,
gives a steady heat, and burns for a longer time without attention
than wood. Stoves for burning oil and gas have become popular, and are
very convenient and satisfactory for cooking purposes.

OIL.

Oil is considered to be the cheapest fuel.

GAS.

Gas is a very satisfactory fuel for cooking purposes, but can only be
used in certain localities.