amino acids as are not or cannot be absorbed may be acted upon by putrefactive bacteria, and the amino acids especially susceptible to such action are tyrosine and tryptophan. Many compounds including phenol may be formed from tyrosine. Besides indole and skatole, the more commonly recognized members of the putrefactive group, Underhill describes another type of putrefactive products, the amines. Tyramine is formed from tyrosine and resembles epinephrine chemically and pharmacologically. Tyramine occurs in ergot and causes contraction of the uterus. While tyramine is produced in the intestine, Underhill says it may also be ingested with such foods as Camenbert, Roquefort and other cheeses.

The production of this blood-pressure-raising substance in the intestine and the ingestion of food containing it should apparently be prevented in high blood-pressure cases. Normally there is about 1 part of epinephrine in 100,000,000 parts of blood.

Many other amines, more or less poisonous to the system if largely absorbed, are produced in the intestine by the activity of putrefactive bacteria; hence the necessity of preventing putrefaction by diet and catharsis. The amount of putrefaction in the intestine, namely, the amount of indole, skatole, etc., is indicated by the amount of indican and ethereal sulphates in the urine.

The stomach absorbs but little protein digested products, but the intestine absorbs not only the amino acids, but perhaps proteoses and peptone, although Underhill states that the proteoses and peptones may disappear from the intestines, because they break up into amino acids and are absorbed only as the latter.

Tissue breakdown, or tissue waste, perhaps means again destructive metabolism to amino acids, to again be built up into products for excretion as urea, creatin, creatinin, etc. The `amount of urea excreted a day is about 30 grams, and it is now known that it is not all produced in the liver as once thought, but is produced by all the tissues of the body. If there is plenty of water in the tissues and the kidneys are healthy, urea is rapidly excreted in the urine. If the kidneys are diseased

and cannot excrete the urea, it stores in the blood and tissues though some may be excreted in the bile. Hence the advisability of catharsis in such conditions. Urea is not a dangerous toxin, and "uremia" is misnamed. Other substances retained with urea are more toxic.

The skin cannot excrete much nitrogen, hence not much urea even in kidney defect. Normally the skin excretes less than 1 gram of nitrogen per day.

Underhill states that "an amino-acid may be regarded as an organic acid in which one hydrogen is replaced by the amino group (N H2)." An amino acid leaves the body as urea, carbon dioxide and water. If this normal change does not occur, other undesirable products may occur, according to Underhill, as for instance, leucine may become keytone acid, and keytone acid a fatty acid, and this by another chemical change may become acetone and acetic acid, and the factors of acidosis are in evidence. In a diabetic metabolism leucine may change to beta-oxybutyric acid instead of to acetone.

Under certain conditions, notably in diabetics on a starchand sugar-free diet, protein may furnish large amounts of sugar. In acidosis creatin may appear in the urine without carbohydrate starvation, but alkalies given freely and early may prevent creatinuria.

There is, according to Underhill, no evidence to show that any aminoacid is formed in the body by synthesis except glycocoll. Urine acidity is increased by whole wheat bread and by all cereals, and decreased by such fruits as oranges, apples, cantaloupe, and bananas.

VITAMINES

To Doctor Thomas B. Osborne, Professor Lafayette B. Mendel, McCollum and others must be given the credit of demonstrating by long experimentation on growing animals the presence in some foods and the absence in others of certain elements with which animals grow and thrive and without which they fail to grow and lose weight. These essential substances are termed vitamines, some of which are water-soluble and some fat-soluble.

The fat-soluble vitamines are necessary for the growth of animals and for their proper nutrition. These vitamines occur in butter (milk fat), egg yolk, cod liver oil, and in more or less of the yellow fats of animal origin, but are deficient in the fat of the pig, according to McClendon. Fat-soluble vitamines are also present in carrots, potatoes, and bananas. Oleomargerine when made of meat fats contains some vitamines satisfactory for growth, but margerines made from nut oils are deficient in vitamines, although there may be a little in peanut oils and peanut butter. Animal oils may lose their vitamines if they are subjected to hardening by chemical processes, but Osborne and Mendel found that the vitamine of butter is not destroyed by a year of cold storage.

Osborne and Mendel found that phosphates deposit in the urine of animals if they are not fed a sufficient amount of fatsoluble vitamines.

It has long been clinically known that the administration of cod liver oil and phosphates was of benefit in rickets and in cachectic children, and seemed at times to prevent rickets, and, lately, Hess has demonstrated that cod liver oil is of great benefit in this disease. After long feeding tests he does not believe that privation of fat-soluble vitamines is a cause of this disease. However, some vitamine in the cod liver oil may be of active benefit. It would seem that, when a child's digestion is disturbed by an ordinary amount of fat and yet less fat allows emaciation, cod liver oil in small amounts will solve the nutrition problem.

The water-soluble vitamines are necessary for appetite and nutrition, and in their absence physiologic disturbances occur. Water-soluble vitamines are found to a small extent in ordinary beef, but more especially in the glandular tissues, such as the liver, kidneys and pancreas. Yellow corn meal contains a watersoluble vitamine, and Osborne and Mendel have shown that the tomato is rich in water-soluble antineuritic vitamines and in fat-soluble vitamines (fat-soluble A) which are characteristic of milk fat and egg fat. Tomatoes have also been shown to have antiscorbutic properties, even when dried or canned.

The antiscorbutic vitamines are water-soluble, and they are

found in oranges, lemons, tomatoes, and in some other foods. Feeding these foods will prevent and cure scurvy. The antiscorbutic dose of orange juice is about a tablespoonful, but larger doses may at times increase the child's weight. Osborne and Mendel have shown that orange juice also has a water-soluble B, the antineuritic vitamine, as well as its antiscorbutic vitamine. They have also found this vitamine in the inner peel. Antiscorbutic vitamines are also more or less present in fresh vegetables, as cabbages, spinach, turnips, and the acid fruits, and generally they are not destroyed by cooking.

The antineuritic vitamines are also water-soluble. They are found in yeast and in the outer shell of many cereal foods, and, as above stated, in orange juice. A proper amount of these foods will prevent the occurrence of beriberi. A diet more or less limited to polished rice has been the most frequent cause of this disease.

It will probably be demonstrated that pellagra is due to privation of vitamines. In the absence of these there is a tendency for the animal, and probably for the human, to acquire infections, especially of the mucous membranes of the alimentary tract, and such infection adds its symptoms to that of the original pathologic condition.

Normally fresh, unheated milk contains, according to Osborne and Mendel, all the vitamines necessary for growth and health. Some of these vitamines are destroyed by pasteurization, and perhaps all are destroyed by more rigorous modes of sterilization.

The mother's mammary glands during lactation apparently have the ability to select vitamines from her blood, thus rendering her milk a most perfect food for the growth of her child. The mammary glands probably do not synthetize these vitamines, hence if the mother's food is inadequate for her own health and for the proper vitaminizing of her milk, the baby will suffer. Also, her milk may contain a sufficient amount of one or more vitamines, but be so deficient in another vitamine that the child will suffer accordingly. A lack of vitamines in the food may not only cause the mother to lose her appetite, but also her child may refuse to nurse.

Osborne and Mendel have found that cow's milk is not very

rich in water-soluble vitamines, hence if for any reason the child takes an insufficient amount, or the milk is too diluted, symptoms of scurvy may develop. Also in such artificially fed infants some fruit juices, generally best as orange juice, should be added to the diet.

Osborne and Mendel and others have shown that milk is comparatively low in antineuritic vitamines. Hence if diluted, or not enough is taken, the child receives an insufficient amount of this vitamine. To meet this need, Daniels, Byfield and others' suggest a vegetable soup, especially prepared, to use as a diluent for milk rather than water. They found when this was added in sufficient amount to the child's nutriment that normal growth was caused. Their feeding experiments seem to prove that diluted cow's milk is insufficient in antineuritic vitamines, while mother's undiluted milk is generally sufficient in this needed element of nutrition.

An insufficient amount of vitamines in the milk may lead to structural trouble in the child later, such as rickets. Also, an insufficient amount of vitamines lowers normal immunity to infection, as evidenced for instance, by inflammation of the eyes occurring after they have become abnormal from privation of fat-soluble vitamines.

Most so-called infant foods do not contain much vitamines, as these occur in the outer husk or shell of cereals and are largely lost by milling; hence the higher refined the flour, the less vitamines it contains. Too finely milled corn and barley have also lost their vitamines. Barley contains a water-soluble vitamine, and Osborne and Mendel have found that the soy bean contains both water-soluble and fat-soluble vitamines. Besides being of high protein value, the soy bean also contains a large amount of oil, hence this legume is a very valuable food.

Experiments have been made to determine whether or not dried vegetables and dried fruits have lost their vitamine content, and it seems probable that at least they are not wholly lost by such treatment, but prolonged cooking of fresh, clean vegetables is not advisable, if the vitamines are not to be diminished in amount. However, canned foods, if there is any 1 Amer. Journ. Dis. of Child., Dec., 1919, p. 546.