The literature on this subject is both considerable and conflicting. It seems pretty well established that the bitters have no action on the pepsin-hydrochloric-acid digestion itself, except possibly in way of slight retardation. This slight retarding action is of no practical significance, especially when the bitters are taken 20 or 30 minutes before the meal, or even just before the meal, because of the great dilution with gastric juice, saliva, and the fluids of the food. The literature also points to the conclusion that by themselves the bitter tonics are incapable of causing secretion of gastric juice, either by acting in the mouth or in the stomach. Pavlov noted in dogs that the bitters acting in the mouth cause a copious flow of saliva, but leave the gastric gland perfectly quiescent; and not even when introduced into the stomach do they cause secretion of gastric juice.

Some observers (Reichmann, Scheffer, and others) have reported that as long as the bitters remain in the stomach they depress or diminish the secretion of gastric juice, and this led to giving the bitters from 10 to 30 minutes before the meals.

Do the bitter tonics augment the secretion of gastric juice indirectly by increasing the excitability of the nerve-endings of taste in the mouth, and possibly the nerves of appetite sense in the stomach ? This is the view emphasized by Pavlov, but he does not adduce any experiments in its support. The work of Borissow seems to confirm it, however. Borissow reports 12 sham-feeding tests on one dog with gastric fistula and esophagotomy. Six of these tests were made after giving the dog tincture of gentian in the mouth. In both series of tests the sham feeding was continued for 1 minute and the gastric juice collected for 2 hours following the sham meal. In the case of the gentian series, the sham feeding was instituted as soon as the profuse salivation induced by the bitters had ceased. Borissow obtained the following results:

There was no difference in the acidity and the pepsin concentration of the gastric juice of the two series, but the average excess of gastric juice in the gentian series is striking. However, it may be questioned whether a short series of tests on one animal can be held as conclusive, especially in view of the great individual variations (over 100 per cent) within each series.

Experimental Procedure On Man

It will be recalled that Mr. V. has the esophagus completely restricted at the level of the upper end of the sternum, so that nothing can be swallowed from the mouth and reach the stomach via the esophagus. Above the constriction the esophagus is somewhat dilated so as to hold about half a glass of liquid. These conditions serve admirably for studying the influence of the bitters on the secretion of gastric juice.

On all test days 100 c.c. of water were put into the stomach 120 and 60 minutes before the meal, so as to insure a completely empty stomach. The tonics were introduced into the stomach via the fistula 15 to 30 minutes before mealtime. In the series of tests with the tonics in the mouth, these were put into the mouth and swallowed into the esophageal pouch 10 minutes before the meal. They usually had to be expectorated before the meal actually began, because of the salivation induced by them.

In all three series of tests the gastric juice was collected in the course of the first 20 minutes during which Mr. V. was chewing his food in the usual way, preparatory to putting it into the stomach by means of a syringe. We are therefore dealing with the appetite gastric secretion only.

The stomach was invariably emptied just before Mr. V. started to eat, and a record was kept of the quantity, acidity, and pepsin strength of this juice found in the empty stomach, as it was thought that the quantity and quality of this juice might serve to indicate the physiologic condition of the gastric glands, irrespective of the condition of the appetite.

The experiments were made during the period from April to November, 1914. The tests with the tonics were interspersed with controls without the tonics all the way, so as to eliminate as far as possible the errors from variations in nutrition, appetite, etc., associated with variations in climate and bodily activity.

It was aimed to make these tests a mere incident in Mr. V. daily routine. For that reason no special dietary standard was fixed. The ingredients of the noonday meal Mr. V. selected for himself at a nearby cafeteria. He naturally selected what appeare to him most palatable from day to day. The evening meal wa taken in the same boarding-house throughout the experiment; period. Mr. V. stated that the boarding-house meals were very much the same from week to week, and were less palatable than the noonday meal.

The tonics used (in therapeutic doses) were tinctures of gentiai quassia, columba, humulus, and condurango, and elixir of quinin< strychnine, and iron. Most of the tests were made with the ger tian tincture and with the elixir.

In order to exclude all possible psychic factors, Mr. V. was not told of the purpose of the experiments. He went about his daily work, taking his usual food at the usual time, while now and the a tonic was given and the appetite secretion measured. We thin it may safely be concluded that such psychic factors as faith in the potency of or hope of improvement from the drugs was entirel eliminated. Nor was the taking of any of these tonics by th mouth disagreeable or loathsome, such as might induce psychic depression.

Table V. Gastric Juice Secreted By Mr. V. During The First Twenty Minutes Or Chewing Food

Tests to the number of 50 were made with bitters in the mouth and 35 with bitters in the stomach, together with 51 control tests These are summarized in tables. The lunch and supper series are tabulated separately, because the appetite gastric secretion was uniformly less at the evening meal. This is probably due to less palatable food at the evening meal (absence of variety in the food, inferior cooking).