able condition for the diastatic action of ptyalin, under most circumstances, appears to be a neutral condition of the fluid together with the presence of more or less proteid matter. The addition of very small amounts of hydrochloric acid to dilute solutions of saliva, giving thereby a small percentage of acid-proteids, appears to still further increase the diastatic action. Under such conditions a minute trace of acid appears to further increase the action."

In the stomach the fundus is never as acid as the pyloric portion. This fact enables salivary digestion to continue in the fundus for some time before there is free hydrochloric acid present. This has been made use of in making a diagnosis of the part of the stomach involved in carcinoma. If a palpable tumor be found and the stomach contents give a reaction for free hydrochloric acid it is assumed that it is a carcinoma of the pylorus, as a tumor inhibits the secretion of the glands in the part involved. If hydrochloric acid be absent this would be suggestive of cancer of the small curvature.

When we have an excessive acidity of the gastric contents, due to some pathologic disturbance, the pyloric sphincter and antrum are apt to contract together, which usually causes gastric colic. It has been shown that free hydrochloric acid and not an enzyme causes the inversion of cane sugar in the stomach.

Pawlow has proved that the reaction of the food influences the closing and relaxation of the pyloric sphincter. Free hydrochloric acid in the stomach opens the pylorus. This acid acting on the intestinal mucosa reflexly closes the pylorus. Just as the pylorus closes, the pancreatic juice and bile gradually neutralize the acid chyme and this allows the free acid in the stomach to again open the pylorus and a new supply of the stomach contents enters the duodenum. On account of this great acidity the intestine is never overburdened with too much food at one time. Just as soon as a certain amount of the acid stomach contents enters the duodenum the pylorus closes to prevent any more from passing through until the pancreatic juice has had time to act upon the food in the intestine. Proteids take up a great deal of hydrochloric acid and require a longer time to give a reaction for free hydrochloric acid than. the carbohydrates. For this reason the pylorus opens sooner after a carbohydrate diet than a proteid diet.

This knowledge is extremely valuable to us in the treatment of disease. In cases where hydrochloric acid is secreted in insufficient quantity the patients are susceptible to diarrhea. We reason that when the pylorus relaxes and allows the stomach contents to empty itself into the duodenum, there is not enough acid in the duodenum to reflexly close the pylorus, and thus the duodenum is over-burdened and the intestinal mucosa is irritated, which leads on to a condition that superinduces a chronic diarrhea. The acid chyme poured into the duodenum stimulates the flow of the pancreatic juice. The emulsification of fat in the intestine can only take place in an alkaline medium.

It is exceedingly interesting to know that pepsin and rennin in the stomach contents are not secreted as such, but are secreted as pro

is not secreted in the stomach. If found it is either introduced as such in the food or it is the result of fermentation. Lactic acid fermentation takes place easily in carcinoma of the stomach, especially when there is an obstruction at the pylorus. When the motility of the stomach is not involved there is no lactic acid present. Lactic or any other organic acid is not a normal constituent of the gastric juice. Organic acids are found in abundance in the upper part of the small intestine.

It is a peculiar fact that the ferments stored up in the pancreas are inactive zymogens. It seems that the intestinal juice has the power of converting the proenzymes of the pancreas into active ferments. It has been repeatedly demonstrated that the juices taken directly from the pancreas lack the proteolytic power which is usually found after they have come in contact with the succus entericus. If a pancreas be chopped up and one-half of its juice be tested for its proteolytic power, without coming in contact with the intestinal juice, and the other half be tested after it has come in contact with the intestinal juice, the proteolytic power of the latter is astonishing. The intestinal juice has the remarkable property of activating the inert trypsinogen into active trypsin by a ferment called enterokinase.

The secretion of the pancreatic juice is stimulated by a substance called secretin. The acid from the stomach produces this secretin in the intestine from some unknown substance and this secretin is absorbed and has the power of stimulating the secretion of panocreatic juice. This can be accomplished by injecting secretin hypodermically, but is apt to produce ulceration of the intestine.

1. Beaumont, Observations on Gastric Juice, 1833.

2

Kussmaul, Ueber die Behandlung der Magenerweiterung durch der Magenpumpe, 1867.

3. Ewald, A Ready Method of Washing Out the Stomach, 1875.

4. Pawlow, Die Arbeit der Verdauungsdriisen, St. Petersburg, 1898.

32 Adams Avenue West.

THE "INFERENCES” OF WILLIAM BEAUMONT CONCERNING

GASTRIC DIGESTION.
HERBERT M. RICH, M. D.,
Detroit,

The epoch-making book of William Beaumont entitled "Experiments and Observations on the Gastric Juice and the Physiology of "Digestion," was published at Plattsburg, New York, in 1833. At the conclusion of the volume Beaumont gives fifty-one "Inferences from the foregoing Experiments and Observations." These "Inferences" contain the major conclusions at which he arrived after several years' experimentation upon Alexis St. Martin, the back-woodsman, who had a gastric fistula. In order to appreciate what radical advances were really marked in gastric physiology by his labors, it has seemed to the writer worth while to compare his writings with contemporary statements on the same subjects.

For this purpose, "The Principles of Medicine, Founded on the Structure and Functions of the Animal Organism," by Samuel Jackson, M. D., Assistant to the Professor of the Institutes and Practice of Med

icine and Clinical Medicine in the University of Pennsylvania, was taken as the most representative book of the time. It was published in 1832, and consequently antedated Beaumont's publication by only one year. The volume was widely used in America as a text-book of physiology and may probably be said to represent quite correctly advanced medical opinion of those days. As we contrast the statement of the two books, one gets a better idea of how thickly the mists surrounded the subject of gastric digestion and how clear and strong was the flood of truth which Beaumont cast upon it.

So little was actually known to be true concerning the physiology of digestion that no theories had been offered about many of the details recorded in the "Inferences," and first observed by Beaumont. His conclusions are given in order as he numbered them, and statements on the same subject by Jackson follow in smaller type.

I.

Inferences from the foregoing experiments and observations.

1. That animal and farinaceous aliments are more easy of digestion than vegetable.

2. That the susceptibility of digestion does not, however, depend altogether upon natural or chemical distinctions.

That digestion is facilitated by minuteness of division and tenderness of fibre, and retarded by opposite qualities.

4. That the ultimate principles of aliment are always the sam, from whatever food they may be obtained.

5 That the action of the stomach, and its fluids are the same on all kinds of diet.

6. That the digestibility of aliment does not depend upon the quantity of nutrient principles that it contains.

7. That the quantity of food generally taken, is more than the wants of the system require; and that such excess, if persevered in, generally produces, not only functional abberation, but disease of the coats of the stomach.

8. That bulk, as well as nutriment, is necessary to the articles of dict.

9. That oily food is difficult of digestion, though it contains a large proportion of the nutrient principles.

10. That the time required for the digestion of food, is various, depending upon the quantity and quality of the food, state of the stomach, etc.; but that the time ordinarily required for the disposal of a moderate meal of the fibrous parts of meat, with bread, etc., is from three to three and a half hours.

II. That solid food, of a certain texture, is easier of digestion, than fluid.

12. That stimulating condiments are injurious to the healthy stomach.

13. That the use of ardent spirits always produces disease of the stomach, if persevered in.

14. That hunger is the effect of distention of the vessels that secrete the gastric juice.

15. That the processes of mastication, insalivation, and deglutition, in an abstract point of view, do not, in any way, affect the digestion of food; or, in other words, when food is introduced directly into the stomach, in a finely divided state, without these previous steps, it is as really and as perfectly digested as when they have been taken.

16. That saliva does not possess the properties of an alimentary solvent.

17. That the first stage of digestion is effected in the stomach. 18. heit.

That the natural temperature of the stomach is 100° Fahren

19. That the temperature is not elevated by the ingestion of food. "The food in the stomach is supjected to a temperature of from 100 deg. to 102 deg. Fahr. This circumstance, and the constant agitation it experiences, are important aids in indigestion. At the same time, a constant supply of the fluids concerned in digestion, is an indispensable requisite for its regular performance."

20. That exercise elevates the temperature; and that sleep or rest, in a recumbent position, depresses it.

"Fibrin is more nutritive and exciting than gelatin or albumen; Its digestion is always attended with heat."

21. That the agent of chymification is the gastric juice.

"Such being the character of chymification, it remains to be examined, what are the means effecting this process. Various conjectures have been resorted to for an explanation of the phenomena of digestion. Putrifaction, maceration, trituration, fermentation, and solution, have each been suggested as the means of its performance; they have each, in turn, possessed their advocates, and enjoyed for a term a certain celebrity. In the received systems none of them are admitted as entering into the process of digestion. Spallanzani, it is supposed, successfully rebutted the pretensions claimed for them; and, amongst the majority of physiologists, his hypothesis of a specific solvent gastric juice is generally adopted.

Chymification would, then, be a purely chemical operation, having a strong analogy to the chemical analysis by which substances are reduced to their proximate elements.

"The existence of a special fluid, possessed of solvent powers, and accomplishing digestion, is an hypothesis assumed, rather than a demonstrated fact. Spallanzani having, by his admirable experiments on digestion, attempted to disprove the, then, admitted doctrines of trituration, maceration, putrification, etc., as the efficient agents of digestion, imagined a peculiar fluid, he named gastric juice, as the means of its performance. This fluid, he conjectured, acted in the manner of a chemical solvent, was always identical, and accumulated in the stomach during fasting. This hypothesis was very generally received, is adopted by most phygiologists of the present day, and often governs the practice of physicians in the treatment of indigestion; yet, it cannot be denied, that the evidence on which it reposes is slight and inconclusive. Its correctness has been challenged, first, by M. de Montegre, and subsequently, by M. Chaussier, whose experiments and obser vations are conclusive against the existence of a gastric juice, such as is supposed by Spallanzani.

Many attempts have been made to analyze the assumed gastric juice, and to determine its specific characters, but they have all failed in the contemplated object. M. de Montegre, who was gifted with the power of evacuating his stomach at leisure, and could, thus, collect the fluid of the stomach, found it to differ very little from saliva. When it was not acid, it, then, resembled perfectly pure saliva; and when it was acid, it appeared merely as a modification that fluid had undergone in the stomach. Tiedemann and Gmelin, in their highly interesting researches on digestion, renew the doctrine of Spallanzani, and suppose a special fluid to be secreted by the stomach during the act of digestion, by which the aliment is dissolved. This inference is adopted from the small quantity of fluid found in the stomach after prolonged fastings and its acid character, when its secretion has been excited by mechanical irritation, or the stimulus of aliment;

a character that does not belong to saliva. Notwithstanding the authority of those able investigators, sustained also by the similar opinion of MM. Leuret and Lassaigne, I am still disposed to doubt the reality of a special gastric fluid, and to regard the assumed gastric juice as no other than the saliva, swallowed and mixed with the secreted mucus and exhaled fluids of the mouth, pharynx, aesophagus, and stomach.

"From the villi, a fluid, said to be albuminous, is exhaled; and the follicles secrete mucus. No other source of a gastric fluid exists than these, and they do not appear to be different from the same structures, in other portions of the mucus tissues. This circumstance renders exceedingly equivocal the existence of a specific gastric juice, the pretended solvent of food. It would be a perfect anomaly in the economy of nature; for, whenever a fluid having specific properties, and destined to important offices, is to be formed, a complex secretory apparatus is appropriated for the purpose.

It has been conjectured that the saliva proceeding from the different glands, was not exactly the same. This opinion is sustained chiefly on the number of its sources; as it was supposed nature would not multiply the number of glands, when two on each side might have sufficed, if mere quantity was the object. But in the provision of important functions, nature often multiplies the organs, to diminish the risks arising from accidents. Saliva is constantly swallowed, so that the stomach is in some respects, a reservoir of saliva. There is every probability that no other gastric juice really exists than the salivary fluids mixed with mucus, etc."

"From all the researches as yet instituted into the nature of the gastric juice, it does not appear to me, we are authorized to assume the existence of a special gastric juice, endowed with peculiar and solvent properties for the performance of digestion. The absence of a special apparatus for its secretion, has already been noticed as an anomaly; and, it is generally true, that, what are supposed to be anomalies in nature, or violations of a general law, are, in reality, founded in an ignorance of the facts, or on suppositious facts not truly existing. That the saliva, which on the supposition of a solvent gastric juice, would be of no other use than to moisten the food, should have provided for its secretion a large glandular apparatus, while the more important fluid, the gastric juice, should be a mere exhalation, would be an anomaly violating grossly the general phenomena of the animal organism. The presumed gastric juice is, then, we are justified in concluding, no other than the salivary, buccal, pharyngeal, oesophageal, and stomachical follicular secretions and exhalations, collected in the stomach.

Notwithstanding all that has been done in the investigation of this function, chymification is not yet properly understood, and new researches must be instituted before it can be regarded as finally settled. The hypothesis of Spallanzani, of a single and uniform specific solvent juice, producing, with all the varieties of aliment, a single and constant product, has not been sufficiently verified by experiment or observation; it has no analogy in nature; and without far more weighty evidence in its favor ought not to be adopted."

22.

That it acts as a solvent of food, and alters its properties. 23. That its action is facilitated by the warmth and motions of the stomach.

24. That it contains free muriatic acid and some other active chemical principles.

25. That it is never found free in the gastric cavity; but is always excited to discharge itself by the introduction of food, or other irritants.

"Now it was observed by Montegre, that the fiuid of the stomach was not acid previous to digestion, but that acid was manifested when food was in the stomach, and, consequently, exposed to irritation. Tiedemann and Gmelin confirm this observation, for they found, when the stomach was not mechanically irritated, the fluid in the stomach was often free from muriatic acid."

26. That it is secreted from vessels distinct from the mucous follicles.

27. That it is seldom obtained pure, but it is generally mixed with mucus, and sometimes with saliva. When pure, it is capable of being kept for months, and perhaps for years.