First, to change the mechanical condition so the digestive juices can act more freely on the mass.

Second, to make it more acceptable to the palate and stimulate the flow of the digestive fluids.

Third, to kill by heat pathogenic germs and parasites often present in uncooked food-stuffs. The typhoid bacillus, the trichina, and the tapeworm are examples.

In cooking starchy vegetables the heat ruptures the cell walls and makes the food more palatable.

The caramel produced also adds to the flavor. In baking bread, cakes, etc, the aim accomplished is to make them lighter and more palatable. This is also aided by yeast and baking-powders. In cake-baking the same effect is produced by adding white of eggs, beaten light, to the mass. Raw vegetables are more dangerous to eat than well-cooked vegetables. The same is true of oysters and clams, more especially of oysters. Salt oysters, as a rule, are not dangerous. We get few salt oysters in our markets. The trick of the trade is to bloat them in fresh water to make them measure up and look plump. Here is the danger, - the fresh water used may be contaminated. This bloating of oysters should be stopped by law in the interest of the public health.

Food too far gone, or kept too long, is liable to ferment, and the deadly ptomaines develop, and the heat of cooking does not even destroy their activity. Thus we get cheese poisoning, icecream poisoning, fish poisoning, meat poisoning, etc Often interesting and startling individual peculiarities are developed. I have known more than one person who never could eat even the freshest fish without suffering from a species of ptomaine poisoning. Again, on some, mutton, eggs, and other unlooked-for food-stuffs have a poisoning effect Daintiness in serving and cleanliness in preparing foods are absolutely essential to comfortable and safe living.

The chemistry of cooking is most interesting and important, but rather foreign to my purpose, and would take up too much space in this work. The reader is referred to books which take up this subject. One by W. Matthieu Williams, "The Chemistry of Cooking," is among the best.