New Mexico, Oregon, Utah and Virginia; many of them have already been particularly mentioned. Some of these springs flow from the earth in the neighborhood of old extinct volcanoes; their temperature is very great, from 150° F. to 195° F. These waters do not, however, contain any active mineral ingredients. They are rarely used for drinking purposes, but are used mainly for thermal baths. The places where these springs are located are important watering places where baths of the most luxurious and elaborate description are provided. The waters are used in every conceivable form for therapeutic purposes. Great curative powers are claimed for these waters in gout and rheumatism in the joints and elsewhere; in nervous disorders, as in neurasthenia, sciatica, paralysis; in spinal disorders and chronic diseases of bones and joints. The treatment is aided by climatology, trophotherapy, thermotherapy, electrotherapy, massage, Swedish and other gymnastic movements.

Mud Baths. At some of the watering places, mud baths are very popular. They are prepared by mixing well seasoned earth containing more or less of the mineral substances which make the water of medicinal value. Slime baths consist of the mud from the bottom of a pond or river, which is rubbed over the body before bathing. Each of these methods is supposed to accentuate the action of the water in certain cases. Mud baths are claimed to be useful in chronic rheumatism, gout and the various uterine ailments of women. They are contra-indicated in valvular diseases of the heart and chronic Bright's disease. Carbonic acid. baths are indicated in neurasthenia, diseases of the reproductive organs and sexual impotency. The principal thermal waters in the United States are to be found in the following locations: Arkansas, Arizona, California, (Buncombe County) North Carolina, (Charleston Artesian) South Carolina, Colorado, (Merriweather) Georgia, Idaho, Michigan, (Volcano) Nebraska, New Mexico, Oregon, Utah, Virginia and West Virginia.

WATER CURES.-In order to obtain the best results from water cures, they should always be carried out at the resorts. Under exceptional circumstances a water cure may be ordered at the patient's home, but the results are never quite so satisfactory as when the patient goes to a watering place. For not only will he have the advantage of the baths and water at the springs, but also in addition, the value of the change of climate, scene, plenty of outdoor exercise and freedom from care and worry.

The methods and the diet at the different institutions vary greatly and for the most part unnecessarily so. In many of these watering places methods are empiric and are not founded on any sound basis. Certain

foods are forbidden for the most fanciful reasons. Again, the routine and diet at many resorts are alike for all patients, regardless of their ailments. An important factor overlooked at these water-cure resorts is the abuse of drinking water. Patients with weak hearts, chronic nephritis or those suffering from atony or dilatation of the stomach may take a considerable amount of water without overtaxing the excretory organs. For instructions as to diet in the various diseases, the reader will be referred to Volume III of this work.

Water Drinking.—Hawk(7), in a series of beautiful and convincing experiments, arrived at the conclusion that copious water drinking caused an increased excretion of nitrogen and phosphorus in the urine. The increase in the amount of nitrogen eliminated is due, primarily, to the washing out from the tissues of the urea the nitrogen previously formed, but not removed by the normal processes, and secondarily, to a stimulation of the protein catabolism. The increase in the excretion of phosphorus is due to increased cellular activity and the accompanying catabolism of nucleins, lecithins and other phosphorus-containing bodies.

Strauss (8) says that increased supply of liquids increases the excretion of the products of protein metabolism, but does not hasten the metabolism itself. The excretion of liquids is accompanied by loss of body weight dependent on removal of nitrogen waste, but not on loss of fat.

WATER DRINKING AT MEALS.-Fowler and Hawk (9), continuing their studies on water drinking in the human subject, investigated the effect of the copious ingestion of water with meals. The subject of the experiment was placed on a normal, constant diet and by means of a preliminary period of sufficient length, was brought to a condition of approximate nitrogen equilibrium. At this point one thousand cubic centimeters of water were added to each meal and continued thus through a period of five days. Immediately following this period came a final period of eight days, during which the original normal constant diet was again maintained and the after-effects of the copious water ingestion observed.

FINAL CONCLUSIONS.-In view of their experiments, they regard the current statements respecting the exceedingly harmful influence of water drinking with meals as misleading and arrive at the following conclusions:

The daily drinking of three liters of water with meals, for a period of five days, by a man twenty-two years of age, who was in a condition of nitrogen equilibrium through the ingestion of a uniform diet, produced the following findings:

1. An increase in body weight, aggregating two pounds in five days.

2. An increased secretion of urinary nitrogen; with excess nitrogen being mainly in the form of urea, ammonia, and creatin.

3. A decreased excretion of creatinin and the coincident appearance of creatin in the urine. The decreased creatinin output is believed to indicate that the copious water drinking has stimulated protein katabolism. The appearance of creatin is considered evidence that the water has caused a partial muscular disintegration resulting in the release of creatin, but not profound enough to yield the total nitrogen content of the muscle. The output of creatin is, therefore, out of all proportion to the increase of the excretion of total nitrogen.

4. An increased output of ammonia, which is interpreted as indicating an increased output of gastric juice.

5. A decreased excretion of feces and of fecal nitrogen, the decrease in the excretion of fecal nitrogen being of sufficient magnitude to secure a lowered excretion of both the bacterial and the non-bacterial nitrogen.

6. A decrease in the quantity of bacteria excreted daily.

7. An increase in the percentage of total nitrogen appearing as bacterial nitrogen. 8. A lower creatinin coefficient.

9. A more economical utilization of the protein constituents of the diet.

10. The general conclusion to be reached as the result of this experiment is to the effect that the drinking of a large amount of water with meals was attended by many desirable and by no undesirable features.

BEVERAGES

In addition to water, there are a number of beverages that serve not only to meet the physical needs of the human economy, but are also taken for their stimulating effect. These beverages afford the stimulation which is necessary in certain diseased conditions and at the same time take the place of water as a beverage. The habit of imbibing socially for the purpose of conviviality unfortunately leads sometimes to the pernicious habit of taking such drinks to excess.

From time immemorial, the ingenuity of man has supplied mildly stimulating non-intoxicating beverages from various vegetable substances. It is somewhat surprising that people of different nationalities, living at different epochs in and under widely different conditions of civilization, should have felt the necessity for, and appreciated the satisfaction to be derived from, the use of this class of beverages. It is even more remarkable that in the beginning they should have selected the plants for making them that continue in use for the same purpose today.

The all important constituent contained in these beverages is an alkaloid, a nitrogenous substance containing stimulating properties. Tea, coffee and cocoa contain, besides this alkaloid, a volatile oil which imparts an agreeable odor and taste to the beverage and a considerable amount of an astringent principle related to tannin, which modifies the taste besides exerting its specific physiological action. Before describing these

beverages, it will be instructive to review briefly the history, mode of manufacture and chemistry of each of them, then to consider their uses in the diet and their action on digestion as a whole.

Varieties of Beverages-TEA.-Tea, the leaves of Thea Sinensis, a subtropical plant introduced into Europe by the Dutch East India Company, is believed to have had its origin in Assam and Burmah. The plant grows wild in the mountainous regions which separate India from China. There are authorities who allege that tea was grown in China before 519 A. D. Reliable authorities state that tea was introduced into Japan in the thirteenth century. Mr. Pepys, writing in his diary in 1660, says, "I sent for a cup of tea, a China drink, of which I had never drunk before." In 1664 the East India Company considered a gift of two pounds of tea to the Queen of England a rare gift. A tea house was established in London in 1657 that sold tea at fifty dollars per pound. Besides China, Japan and Assam, tea is grown in Ceylon, Java and Brazil and for the past ten years tea has been successfully grown in South Carolina. The plant grows best in sub-tropical countries where the rainfall is at least sixty inches or more.

The tea plant when cultivated grows to the height of three or four feet, but if allowed to grow without pruning, it may attain a height of forty or fifty feet. The plants are obtained from seeds and when planted in rows four feet apart and four feet distant, attain in two years a height of two feet. They are cut back to ten inches high and after another year back to fifteen inches high. At three years the mature tree includes a great number of young shoots three feet in height. The plant flushes or sends out shoots four times a year, when the young leaves are ready to pick. The leaves are picked irregularly; some farms pick every fortnight, others only twenty times per year. They are carefully picked with the thumb and forefinger. One hundred pounds of fresh leaves yield about twenty-five pounds of tea.

GREEN AND BLACK TEA.-Tea is not green or black according to separate species of tea plant, but derives its color from the difference in mode of treatment of the same plant. Green tea is made in Japan by steaming the leaves before they are rolled and dried, while the Chinese wither the leaves in a pan at the temperature of 160° F. Black tea is obtained by allowing the green leaves to wither in the sun; then they are rolled until they become soft and "mashy," the object being to break up the fibers and cells of the leaf and liberate the constituents, so that they may afterwards be more easily extracted. They are then made into balls and allowed to ferment.

The process of fermentation oxidizes a certain portion of the tannin in the leaves, converting it into less soluble forms while the essential oil content is increased and a certain amount of bitterness developed. When the fermentation is complete, the leaves are again exposed to the sun and dried in an oven. The main difference, then, between green and black tea lies in the fact that black tea is fermented while the green is not.

QUALITY OF TEA.-The quality of the tea depends somewhat upon the age of the leaves when picked, the younger leaf yielding the best tea. Apart from this cause of variation, teas show marked difference in "body" according to the country and district in which they are produced.

The principal agent that imparts "body" and flavor to tea is oxydase, an enzyme found in the unopened tip-leaf of the young shoot (10), which diminishes with its growth and expansion. The proportion of this enzyme present in a given sample depends in a measure upon the amount of phosphates in the soil. The enzyme increases during the preparation of the tea as the leaf withers. The leaves containing the highest percentage of the enzyme make the most highly flavored tea.

CHINA AND INDIAN TEAS.-The most famous China teas are: Congou, Oolong, Formosa, Souchong and Bohea (black teas); Hyson, Twankay and Gunpowder (green teas). India Assam or Assam Pekoe are good teas. A good blend is made of China Assam and Ceylon teas together. China tea, such as Moning Congou, is very suitable for persons with weak digestive organs. The Indian teas, especially those produced in Assam, are very strong. Their astringent properties make them powerful teas, not well suited for brewing alone. They are admirable for blending with milder varieties.

COMPOSITION Of Black and GREEN TEA.--The following table from Bannister (11) gives the composition of black and green tea :

ANALYSIS OF GREEN AND BLACK TEA