organs are constantly in motion, producing a more or less constant agitation or churning of the respective contents which serves to intimately mingle the food particles with the digestive juices, thereby accelerating digestion. Hence, everything else being equal, anything which tends to accelerate peristalsis will in turn accelerate the rate of digestion, while, on the other hand, retardation of peristalsis may be accompanied by inhibition of digestion. Lastly, the rate of absorption from the alimentary tract exercises an influence upon the speed of digestion; consequently any agent which, for example, modifies the flow of blood along the gastro-intestinal tract, thus influencing the rate of absorption, may indirectly affect the speed of digestion. It is thus plainly evident that what we term digestion may be influenced through a variety of channels, but the two more important ways in which digestion may be modified are through changes in the rate of flow and composition of the digestive fluids, i. e., changes in secretion, and through changes (either acceleration or retardation) in the rate of digestive action caused by the mere presence of some substance in the digestive mixture, i. e., through a direct influence upon the purely chemical processes of digestion. Moreover, it is obvious likewise that a substance may exercise an inhibitory influence in one direction, as upon the chemical process of digestion, while leading to an acceleration in another direction, as on secretion. Further, a given agent may produce one effect on salivary digestion and quite a different effect on gastric digestion. Obviously, therefore, in studying the influence of alcoholic beverages on digestion, there are many lines of inquiry which must receive attention.

II.

GENERAL CONCLUSIONS AS TO THE INFLUENCE OF ALCOHOL AND ALCOHOLIC BEVERAGES ON DIGESTION.

As already indicated, digestion may be influenced by alcoholic fluids in several ways, notably by influencing the rate of secretion of the digestive fluid, either increasing or diminishing the rate of flow and thereby increasing or decreasing the volume of digestive fluid available, and also by modifying either favorably. or unfavorably the chemical composition of the secretion. Further, the presence of the alcoholic fluid, in the stomach for example, may exercise a direct influence upon the chemical processes of digestion, either augmenting or retarding the natural solvent or digestive action of the secretion. Again, digestion may be influenced indirectly by the action of an alcoholic fluid upon the rate of absorption and upon the peristaltic movements of the intestine, since both of these factors exert an influence upon the rapidity of digestion.

1. GASTRIC DIGESTION.

a. Influence of alcohol and alcoholic beverages on the secretion of gastric juice. The results of the experiments carried out by the writer and his assistants on the influence of alcohol and alcoholic beverages on the secretion of gastric juice lead to some very definite conclusions. The data obtained and presented in detail in the subjoined report tend to show that when alcohol and alcoholic fluids are taken into the stomach there is a marked increase in the flow of gastric juice accompanied by an increase in the content of the essential constituents, pepsin and hydrochloric acid, as well as in the content of total solid matter. Moreover, this stimulating effect of alcohol and alcoholic beverages upon the secretion of gastric juice is not limited to a direct action dependent upon the presence of the alcoholic fluid in the stomach, but is exerted likewise indirectly through the influence of alcohol absorbed from the intestine. Thus, if the

intestine is entirely shut off from the stomach by a ligature at the pylorus, the introduction of an alcoholic fluid into the intestine is followed by a stimulation of the gastric glands accompanied by an outpouring of the gastric secretion. Whiskey, brandy, sherry, claret, beer, and porter, as well as pure alcohol, all agree in producing direct and indirect stimulation of gastric secretion, increasing both the rate of flow of the gastric juice and the concentration of the fluid.

Of special importance in this connection is the fact, brought out by experiment, that when alcohol and alcoholic beverages are introduced into the alimentary tract there is a very rapid absorption of the alcohol into the circulation. The alcohol quickly leaves the stomach and intestine passing into the blood, .this act being accompanied by an inrush of acid gastric juice in large quantity. Even from the stomach, where absorption is ordinarily comparatively slight, the absorption of alcohol goes on with considerable rapidity. Thus, the introduction of two hundred c. c. of thirty-seven per cent. alcohol into the stomach of a dog with the intestine ligated at the pylorus may be followed by the nearly complete disappearance of the alcohol in three hours by absorption through the stomach walls into the blood. When the outlet from the stomach into the intestine is open, then the rate of absorption of alcohol is greatly increased. Alcohol unquestionably disappears from the alimentary tract quite rapidly. Thus, in one experiment, fifty c. c. of twenty per cent. alcohol were introduced into the stomach of a dog with a gastric fistula, and on withdrawal of the stomach-contents half an hour later no alcohol whatever was found in the forty c. c. of fluid obtained. In view of this rapid disappearance of alcohol from the alimentary tract it is plain that alcoholic fluids cannot have much, if any, direct influence upon the secretion of either pancreatic or intestinal juice. Further, it is equally clear that the rapid removal of alcohol from the stomach by absorption must tend to diminish considerably any influence the presence of alcohol might exert upon the solvent or digestive action of the gastric juice in the stomach.

The conclusion is therefore obvious that when alcoholic fluids are taken into the stomach there is first a direct stimulation, leading to the rapid secretion of a powerful gastric juice. This is followed by a more or less rapid absorption of the alcohol

accompanied in turn by an indirect or secondary stimulation of gastric secretion. These conclusions are in accord with many previous observations bearing upon this subject. Thus, in many of the older handbooks of physiology the statement is frequently found that "alcohol is a strong stimulant of gastric secretion,' and it has been a common practice to use alcohol as a means of obtaining gastric juice from dogs with gastric fistula.1 Gluzinski, in 1886, reported that when brandy and dilute alcohol were administered to men these fluids gave rise, after a brief preliminary period, to the formation of a very active gastric juice, rich in hydrochloric acid. Wolff, in 1889, found that cognac in small doses increased the secretion of hydrochloric acid. He reports in addition, however, that in larger quantity it decreases the acidity of the gastric juice. Klemperer, in 1890, observed that moderate doses of alcohol led to a very slight increase in the secretion of gastric juice, while in the same year Blumenau reported that the introduction of twentyfive to fifty per cent. alcohol into the healthy human stomach acts as a secretory stimulant, bringing about an increased flow of gastric juice with rise of acidity. Brandl, in 1892, experimenting with fistulous dogs, found that alcohol — as contrasted with water introduced with foodstuffs into the stomach brings about an unfailing, though not particularly large, increase in gastric secretion. Lastly, Haan, in 1895, with repeated and increasing doses of alcohol observed an augmentation in the acidity of the gastric secretion from the dog, followed after a few days by a diminution in the amount of secretion and a gradual decline in acidity. It is thus apparent that, in a general way at least, there is a perfect agreement between our observations upon this subject and the recorded observations of other physiologists. Further, there is no necessary inconsistency between the stimulating action of alcohol upon gastric secretion and the quite probable detrimental action of larger doses frequently repeated. As stated by both Heidenhain and Lauder Brunton, large amounts of alcohol are regarded as detrimental to the stomach, giving rise eventually to a pathological condition, a statement which is doubtless correct. It has been our aim, however, to ascertain the physiological action of alcoholic beverages upon gastric

1 The authority for these and some of the following statements will be found in the references on pages 251-253 of this report.

secretion, and upon this point our conclusions are quite definite that they act as stimulants.

b. Influence of alcohol and alcoholic beverages on the chemical processes of gastric digestion. Our experiments upon this subject have been very numerous, and for the detailed results reference must be made to the subjoined report. It will suffice here to state merely our general conclusions, bearing in mind, however, that these have to do simply with the action of various alcoholic fluids upon the chemical processes of gastric digestion, i. e., the influence of the presence of alcoholic fluids in the stomach upon the solvent or digestive action of the gastric juice on proteid foods.

Pure ethyl alcohol, when mixed with the stomach-contents or with an artificial pepsin-acid solution, has little or no effect on pepsin-proteolysis when present in small amount, say one or two per cent. of absolute alcohol. Not until the digestive mixture contains five to ten per cent. of absolute alcohol is the action of the gastric juice materially interfered with. With these proportions of absolute alcohol, equal to ten or twenty per cent. of proof spirit, retardation of proteolysis becomes noticeable, while in the presence of fifteen to eighteen per cent. of absolute alcohol digestive action may be reduced one quarter or even one third. Especially noteworthy is the fact that the extent of retardation by a given percentage of alcohol varies greatly with the strength or activity of the gastric juice and with the digestibility of the proteid food. Everything else being equal, the greater the strength or digestive power of the gastric juice, the less is the retardation; while, on the other hand, the weaker the gastric juice, the greater is the inhibitory action of a given amount of alcohol. Normally, however, it is safe to say that until the stomach-contents contain ten per cent. of proof spirit, there is no appreciable retardation of the solvent action of the gastric juice.

Strong alcoholic beverages, such as whiskey, brandy, rum, and gin, ordinarily containing from forty to fifty per cent. of absolute alcohol, have an action upon gastric digestion practically proportional to the amount of alcohol present. Thus, with a vigorous gastric juice, the presence of ten per cent. of whiskey results simply in a slight retardation of digestive action. With a weak gastric juice, the retardation is much greater. When