Animal viscera are eaten to some extent in this country, and some of them are digestible, although none are as nutritious as good meat, and they contain but little nitrogen. With the exception of sweetbread, and in some cases the thyroid gland, they should not be given to the sick.

Sweetbread is most useful in the invalid dietary. It consists of the pancreas of the calf, called by butchers "stomach sweetbread " to distinguish it from the thymus gland of the same animal, called also the "neck" or "throat sweetbread." Either gland is tender and digestible, the thymus somewhat more so than the pancreas, which has larger, more "stringy" blood vessels.

The thyroid gland has been lately shown to possess remarkable power in regulating disordered nutrition in cases of myxcedema, chronic skin diseases, etc. It is usually given as a powdered extract in five-grain doses, but it is sometimes cooked fresh and eaten as a food.

Tripe, made from the third stomach of the cow, when tender and well cooked, is easy to digest, although somewhat too fat. It contains about 16 per cent of fat and 13 per cent of albuminoids - rather more than most viscera.

The heart is sometimes eaten, but the meat is tough and undesirable.

Liver and kidneys are eaten more than any other viscera. If cooked too long they become very hard and tough. Calf's liver is always better flavoured and more tender if the animal has had fresh milk for food and not boiled skimmed milk and slops. Tender liver is more easily digested than kidney, and is fairly nutritious. It should not be allowed diabetics. These foods are often fried or stewed in rich sauces or "devilled," all of which are indigestible modes of cooking.

Brains are fairly digestible, but not nutritious; they contain too much fat and cholesterin for invalids.

Blood has sometimes been used as a fluid food. At one time there was a fashion among consumptives of going to the abattoirs to drink it warm, in the belief that it had some specific curative value for tuberculosis. This, however, is not the case, and it nauseates most persons to taste it, if not to look at it.