This section is from the book "Practical Dietetics With Special Reference To Diet In Disease", by William Gilman Thompson. Also available from Amazon: Practical Dietetics with Special Reference to Diet in Disease.
Bone marrow is an easily digestible and wholesome fat which has long been used as a food. The long bones of the ox are cut crosswise in pieces about two inches in length and cooked with the marrow within them. Red marrow is a useful food in cases of tuberculosis, secondary and pernicious anaemia, and chlorosis. But it is doubtful whether the marrow acts otherwise than 15 in furnishing an assimilable fat to patients who are much in need of such food, and also a very digestible form of iron, which exists in it in considerable quantity. The marrow of young animals, such as the calf or lamb, is preferred for this purpose, because their tissue-building power is so active. Fraser reported the first case of anaemia treated by means of marrow, and he prefers a glycerin extract.
J. S. Billings, Jr., recommends a similar preparation made with sheep's ribs, chopped, rubbed in a mortar with glycerin, macerated and strained.
Henry F. Walker, of New York, uses a sort of emulsion made by mixing thoroughly the red marrow of the long bones of the ox with Cetraria (Iceland moss). This makes an exceedingly agreeable preparation, a whitish paste pleasant to the eye, and tasting not unlike good butter. It may be spread upon bread and eaten three or four times a day.
Pemmican is made of meat cut into slices and thoroughly dried in the sun; to this are added fat, sugar, and dried fruit, such as raisins and currants. It is used on long voyages, especially to the Arctic circle, where a fatty diet is essential to furnish heat and force to enable the body to withstand the rigour of the climate. It is easily masticated, and the sweet fruit promotes the flow of saliva.
Calves' brains and liver contain considerable fat.
Many fish oils have special uses. The Eskimos eat whale and seal oil and blubber, and dugong oil is eaten to some extent in Australia. The oil of the sturgeon is employed for preserving caviare. Turtle oil and butter is made extensively in Brazil from both the eggs and fat of the animal (Clark).
Cod-liver oil will be separately considered.
Eggs contain considerable fat in their yolks. Some eggs, like the plover's, are very rich in this ingredient. They are elsewhere described in detail. (See Eggs, p. 103).
Lecithin is a form of fat contained in a variety of animal cells, but predominating in eggs and brains. Various preparations of it have been placed on the market as food, but it is best to administer it through modification of the dietary by increased use of such foods as eggs and calves' brains.