For medicinal effects several oils are used in a culinary form, whether animal, or vegetable, fixed, or volatile. Likewise certain animal oils can be beneficially rubbed into the skin of persons wasted through long illness, or atrophied by defective nutrition. Neatsfoot Oil, from the heifer, is admirable for such a purpose. Thomson tells in his Seasons about "A little, round, fat, oily man of God".

Neat are cattle of the bovine genus taken collectively, as oxen, bulls, cows, and calves. Shakespeare, in the Winter's Tale, says playfully: -

"We must be neat; not neat, but cleanly, Captain! And yet the steer, the heifer, and the calf Are all called neat".

And again, in Julius Ccesar: -

"As proper men as ever trod upon Neats' leather have gone upon my handiwork".

Another such animal oil is "Trotter Oil," obtained by boiling down the feet, or trotters, of sheep, or calves. The closer the similarity between the fats, or oils, taken as food, and the fat of a person's body, the more readily is the dietetic fat or oil absorbed, and utilized for the bodily wants. Sir Henry Holland advocated the practice of anointing the harsh, dry skin of dyspeptic patients with warm oils, those of a bland animal sort being preferable for the purpose. The yolk of egg, the livers of poultry and fish, and the brains of animals, all abound in oily matter. Gilbert White tells that oil is extracted from Cockchafers in Kent by boiling these creatures, which are collected by the labourers with such view. Cod-liver Oil is universally known, and valued as a typical fatty aliment for consumptive persons, in whom the waste by hectic fever, and often by other bodily losses, is excessive. All the vital constituents of bile are comprised in Cod-liver Oil; but the essential curative action thereof is due to a subtle force residing in its inmost centre, the "very principle, and factor of life." It may be better relished if some catsup is mixed with the oil, or some Liebig's Extract of Meat. Iodine, lecithin, and bromine are constituents of this oil, together with glycerine, resin, margaric acid, therapine, oleic acid, coleine, salts of lime, potash, and sodium.

It is of great service as a food likewise in scrofulous affections of children, and for banishing all strumous diseases of the skin. Only "medicine oil," as it is termed in Norway, should be used, which is extracted reliably from the fresh livers which are pressed without stewing; it pertinaciously retains a fishy flavour, and (together with some other fish oils) embodies a considerable amount of cholesterin, which is a particular alcohol concerned in bile-making, (and to be perhaps therefore suggested curatively for restoring glycogen-producing energies to the liver in diabetes). This occurs also in the fat of certain land animals.

An agreeable, and at the same time beneficial, form of fish oil, as a food, is embodied in the contents of the Sardine box now in such general use. Genuine Sardines from the Mediterranean, as imported from Spain, Portugal, and France, are often small pilchards (Clupea pilchardus). The Californian Sardine is Clupea sagax. These delicate fish must be as fresh as possible when first handled; they are beheaded, and gutted, and allowed to remain on wooden slabs overnight after being slightly salted; next day they are salted again, and allowed to dry; they are then cooked in olive oil, and put into wire baskets to drip. The cooking is a nice process; if it is overdone the scales come off; five, or six minutes suffice for the cooking. When they have become cold the fish are placed on tables to be arranged in boxes amid oil dipped from the barrels; this oil is worth more than the fish, therefore they are packed as close as possible; the boxes are then soldered down, and they are cooked a second time by steam. Small Sardines are the most prized. Occasionally a red coloration of the Sardines preserved in oil may be discovered, this being due, it is said, to a chromogenic bacillus which is then found in large numbers on these Sardines before preservation: it is not at all harmful.

Long ago, in the Treatise of Gonzalo Oviedo (1535), occurred the record: "When the sayd increasyng of the sea commeth, there commeth also therewith such a multitude of the smaule fyshes cauled Sardynes that no man wolde beleve it that hath not seene it." The preserved Sardine is said to have been brought into fashion by Henry the Fourth; this delicate fish has been termed the "Manna of the sea." If properly prepared, and not with too much salt, the longer the tin of Sardines is kept unopened the more mellow do the fish become. Without doubt a good many sprats are put up in tins with oil as Sardines. The abundance of oil, together with incorporated fish-products, make Sardines especially suitable for consumptive patients, also for diabetic sufferers, and for other wasting illnesses, provided the digestive powers do not rebel. The small fish are nicest for eating, and are appreciated best by delicate appetites; thus "the lawyer may find a feast in a box of Sardines, with some biscuits, while the field labourer would look with contempt on such food, and would eagerly turn therefrom to fat pork, and cabbage." "Sardines can supply to the brain-worker the material he needs; likewise the pork and cabbage to the labourer, the heat and energy which he expends." Mr. Dunn, of Mevagissey, in Cornwall, first proposed the preparation of Sardines in this country, but for a long time they were not very popular.

Only sixty years ago, a grocer in Brighton had a small quantity on hand for three years, without being able to find a purchaser for them. It was ordered in the first London Pharmacopceia, 1618, "for use among the poor," that oil of Swallows (Oleum Huundinum) should be employed externally for the cure of rheumatism. This oil was to be made by boiling down young Swallows in oil, together with certain herbs, wine, and May butter. It was ordained with the hope that the stiffened and distorted joints of sufferers would be thus made as lithesome as those of the Swallow or Swift.