FISH FATS. The common fish which contain large amounts of fat are the eel, salmon, herring and mackerel. Sardines contain some fat, but no doubt the oil in which they are preserved exceeds the fish oil in fuel value. Many species of fish are rich in oil. The Eskimo eats whale blubber (fat). The oil of the sturgeon is extensively employed to pre

serve caviare.

COD LIVER OIL.-Cod liver oil is manufactured from the fresh raw livers of the codfish by subjecting them to heavy pressure. It is one of the most easily absorbed of all the oils. Its taste is objectionable to most people. Cod liver oil is much used as a therapeutic agent, and the reader is referred to text-books on materia medica and therapeutics for further information on this product.

VEGETABLE FATS AND OILS

Vegetable Fats and Oils.-Vegetable fats and oils are derived in greatest abundance from the seeds of plants and are extracted by pressing the crushed seeds. Most of the cold drawn vegetable oils from seeds and fruits are suitable for culinary purposes or for the preservation of foodstuffs. The elimination of all fatty acids from edible oils is very important process, brought about by the use of alkalies or alkaline earths during the process of manufacture. These oils should not congeal at temperatures near the freezing point. Olive oil does not congeal, but some other oils, such as cottonseed oil and peanut oil, which contain stearin, have to be demargarined to prevent congealing. To prevent this the oils are stored for the winter months in large tanks to allow the stearin to settle or crystallize out. The clear oil may be withdrawn from this, or the stearin may be removed by filtering or by centrifugalization.

VALUE OF VEGETABLE OILS AND FATS.-Vegetable fats and oils are very valuable for the production of heat and energy for the body. Compared with sugar, vegetable fats are about two and a half times as effective and are to be regarded as a very concentrated form of nutriment.

ABSORPTION OF VEGETABLE FATS.-Unless fats and oils are well emulsified and saponified they will be decomposed in the intestines into fatty acids and glycerin, which recombine when passing through the intestinal wall.

Since vegetable oils are readily absorbed after proper emulsification and saponification, they may be ingested in relatively large quantities, and are extremely useful for the diet in the treatment of certain

diseases. The principal uses of vegetable oils and animal fats like lard are for "shortening" pastry and for frying foods. Fried foods, however, are difficult to digest, because the material becomes saturated with fat, which acts as a barrier to the free penetration of the digestive enzymes. This prevents ready contact with the carbohydrates and proteins of the food substance. If food is to be cooked in "deep fat," the process used in cooking doughnuts, it is important that the heat should be sufficiently high so that very little of the fat is absorbed.

PERCENTAGE COMPOSITION OF OIL-BEARING VEGETABLES.-The following table, from Professor A. A. Church, contains a list of oil-bearing vegetable products, with the percentage composition present in each:

This may be supplemented by the following, which are of less commercial importance: rape seed, mustard seed, tomato seed, raisin or grape seed, apricot and peach kernels, which are all of some commercial value. Flaxseed, from which linseed oil is made, is of great commercial importance.

PALM OIL.-Palm oil is obtained by cold pressing the soft part of the fruit of numerous varieties of palm trees in many tropical countries. It is semisolid at ordinary temperatures and has an agreeable taste. Palm oil is extensively used for food purposes. Its chief constituent is palmitin. The palm nut, from the kernels of which palm nut oil is manufactured, is obtained from the same tree. This product is used in the

manufacture of butterine and other butter substitutes, and is sold as vege

table butter under various trade-marked names. Palm oil or butter is used extensively by the natives in districts where it is produced.

ALMOND OIL.-Almond oil is obtained from either the bitter or sweet almond. The former contains a greater percentage of oil and is more generally used. This almond nut is grown extensively in countries around the Mediterranean Sea. Almond oil is sometimes adulterated with cheaper oils made from apricot and peach kernels. Almond oil is of a clear yellow color and a bland taste.

PEANUT OIL.-Peanut oil is obtained by the cold hydraulic pressing of peanuts. The best quality of peanut oil, called cold drawn oil, comes from the first pressing. Subsequent pressings and pressing with heat yield oil of a lower grade. The residue left is rich in proteins and starch and is valuable as a stock food. The principal use of peanut oil is for a salad oil, either alone or mixed with other oils. Recently it has been largely used as an adulterant for olive oil and is itself sometimes adulterated with cottonseed or poppy seed oils. Peanut oil is an excellent substitute for lard in "shortening" or in other culinary uses. It is superior to most oils for the "deep frying" of foods.

SESAME OIL.-Sesame oil is obtained by pressing the seeds of the sesamum orientale, a native plant of southern Asia. The best grades of this oil are a golden yellow, free from any disagreeable taste or odor, and may be used in place of olive oil for salads. Cold drawn sesame oil is considered quite equal to olive oil as a salad oil. It has a slight amber color, a grain-like odor and a pleasing, bland taste.

POPPY SEED OIL.-Poppy seed oil is made from the seeds of the black and white poppies. These are grown extensively in Europe, Turkey, Persia, India, China and Germany, to extract the oil made from the seeds, as well as the inspissated juice of the same, which supplies the opium of the world. The better grades of poppy seed oil are of a light color and have an agreeable taste. This oil is also much used in foreign countries as salad oil.

OLIVE OIL.-Olive oil is obtained from the pulp and sometimes from the kernels of the olive fruit. The better grade of olives produce from 40 to 60 per cent of oil. It is called virgin oil when taken from the first pressing. The pomace, then taken from the press, reground, mixed with water and repressed, produces a second grade of oil in the process of manufacture. After the high grade oils are extracted, they are further purified by being placed in tanks and washed with water, then allowed to stand until the pulp and gummy material settle to the bottom, when the oil is carefully drawn off. Olive oil is frequently adulterated by the addi

tion of cottonseed oil and peanut oil. Rape seed oil and poppy seed oil are frequently used as adulterants of olive oil in Europe. This can be readily detected by chemical analysis. When pure olive oil from the first pressing leaves the press it is of a dark green color from the presence of chlorophyl, but most of this is deposited in the tanks. Olive oil has a peculiar faint odor and a bland, pleasant taste.

MUSTARD SEED OIL.-Mustard seed oil is produced in Switzerland and Italy and commonly used in those countries as a substitute for olive oil.

CACAO FAT.-Cacao fat or oil of theobroma is one of the few vegetable oils that is solid at ordinary temperatures. It is prepared by pressure of roasted and crushed cacao beans or nibs. This oil is obtained during the manufacture of chocolate. Cacao butter has a pleasant odor and flavor faintly suggestive of chocolate. It is extensively used in pharmacies and in the manufacture of perfumes. On account of its high price it is frequently adulterated with cocoanut oil, palm oil, beeswax and paraffin.

COCOANUTS.-Cocoanuts have long been a source of fat. There are several names for the oil made from this nut, dependent upon the country in which it is made. The meat of the cocoanut includes the milk which is gradually absorbed as the nut reaches maturity. The milk is used by the natives in the same way as cow's milk. The oil is obtained from the sun-dried kernels. This is prepared by the natives by boiling the kernels in water and removing the fat by skimming.

ness.

Cocoanut oil is semi-solid at ordinary temperatures, keeps well and is free from fatty acids. It is seldom adulterated on account of its cheapIt is extensively used for culinary purposes. This oil must not be mistaken for salad oil, to which it is inferior. Cocoanut oil is a fat of moderate consistency, nearly as hard as lard, and has an agreeable flavor, pleasant taste and aroma.

COTTONSEED OIL.-Cottonseed oil is manufactured from the seed of the cotton plant. The seed is passed through machines which remove the linters, when they are transferred to a shelter where the hull is broken and separated from the kernels in a winnowing machine. The kernels are then crushed between massive steam rollers and put into steamjacketed kettles, where they are cooked, with constant agitation. The mass is then shaped into cakes surrounded by cloth and subjected to from 3,000 to 4,000 pounds hydraulic pressure to the square inch. This process yields about 45 gallons of cottonseed oil from a ton of cottonseed. The

oil obtained is purified and the residue from the seed is broken up and ground to a meal and put on the market as a stock food. The process of purifying the crude cottonseed oil is an intricate one. Purified cottonseed oil as a food product has become popular in the last decade. It is practically tasteless and odorless and is as wholesome as animal fat. It is admirably adapted to many culinary uses.

SUNFLOWER SEED OIL.-Sunflower seed oil has not been utilized to much extent in the United States, although the seeds contain considerable oil. In some European countries sunflower seeds are eaten as an ordinary food. The plant is extensively cultivated in Russia, Hungary, India and China for food purposes. The oil made from the seeds is palatable and needs no refining to make an excellent salad dressing. The best grade of oil is obtained by cold pressure of the whole seeds.

CORN OIL.-Corn oil is manufactured from the germs of the grains of Indian corn or maize. The germ contains more than 20 per cent of oil, the odor and taste of which are agreeable. This oil is frequently mixed with other vegetable oils and used largely in the manufacture of oleomargarin and lard substitutes. Corn oil is a by-product of starch and glucose factories and contains stearic, palmitic and oleic acids.

RAPE OIL.-Rape oil is made from the rape seed, which produces an excellent oil for culinary purposes. The "cold drawn" oil is of the best quality. The plant is grown extensively all over Europe, also in India and China. Fresh rape seed oil has an agreeable taste and odor, but on long standing it becomes rancid. The oil is frequently adulterated with cheaper oil, such as cottonseed and hemp seed and poppy seed oil.

MUSTARD OIL.-Mustard oil is an excellent bland oil, sometimes used in place of animal fat for culinary purposes. This oil as extracted by pressure is a by-product in the preparation of mustard as a condiment.

TOMATO SEED OIL.—Tomato seed oil is employed especially in Italy as a salad oil.

APRICOT KERNEL OIL.-Apricot kernel oil and peach kernel oil are both edible oils and important articles of commerce. They are principally used as an adulterant to almond oil.

SOY BEAN OIL.-The soy bean oil contains from 18 to 19 per cent of oil which is of such good quality that it will in time no doubt come into general use.

LINSEED OIL.-Linseed oil is manufactured from flaxseed. It is sometimes used as a substitute for olive oil, but is not very digestible. Its principal use from a commercial point of view is in the painter's trade.