a rare one; and we congratulate the public, and especially the medical profession, that it fell into the hands of one who appreciated its value, and who possessed the requisite intelligence, perseverance, and candor, to make the investigation which it afforded, and to state the results of such investigation, in a plain, simple, intelligible manner, without bias from preconceived opinions, or fanciful hypotheses.

The case which gave rise to these experiments will be understood, from a brief summary of a particular account given of it, in the introduction to the book.

In the year 1822, Alexis St. Martin, then in the employment of the American Fur Company, while at Michillimackinac, where Dr. B. was stationed, was wounded in the side by the accidental discharge of a musket loaded with buck shot. The contents of the gun struck him upon the left side, and passed in an oblique direction forward and inward, literally blowing off integuments and muscles of the size of a man's hand, fracturing and carrying away the anterior half of the sixth rib, fracturing the fifth, lacerating the lower portion of the left lung, and the diaphragm, and perforating the stomach. The progress of the case, after so extensive a wound, involving parts of so much importance, was, of course, slow. The soft parts in the vicinity sloughed away the ribs and their cartilages were successively attacked and destroyed by inflammation, and removed by the surgeon; and it was not until June, 1823, a year from the time of the accident, that recovery, so far as it took place, was completed. At that time, the parts were in the following state: the injured parts were all sound, and firmly cicatrized, with the exception of the aperture in the side and stomach. The perforation was about two and a half inches in circumference; and the food and drinks constantly exuded, unless prevented by a tent, compress and bandage. At the point where the lacerated edges of the muscular coat of the stomach and the intercostal muscles met and united with the cutis vera, the cuticle and the mucous membrane of the stomach approached each other very nearly. They did not unite, like those of the lips, nose, &c., but left an intermediate marginal space, of appreciable breadth, between them, completely surrounding the aperture. This space is about a line wide; and the cutis and nervous papillæ being unprotected, are as sensible and irritable as a blistered surface abraded of the cuticle. The only change which has since taken place, is the gradual falling down from the upper margin of the orifice, of a fold of the coats of the stomach, fitting itself to the aperture, and forming a valve,

which effectually retains the contents of the stomach, even when completely filled.

From that time to the present, St. Martin has enjoyed as good health, and as much vigor, as men in general; has performed, with little or no inconvenience, the duties of a laboring man; married and become the father of a family of children, and has subsisted upon the common food of men in his situation, except when a particular diet has been prescribed, for the purpose of experiment.

There are several plates which are intended to represent the state of the parts, under different circumstances. As these are too imperfect to render any assistance, we are glad that a mere verbal description will render the account sufficiently intelligible.

From this account it will be seen, that the cavity of the stomach is open to the view; that the state of its surface, and of the secretions from it, can be readily examined; that foreign bodies can be introduced and removed at pleasure, and that the changes which have been wrought upon them, at any time after they have been introduced, can be ascertained.

For several years, since his recovery, St. Martin has been retained in the service of Dr. Beaumont, at the expense of much time, patience and money, for the sake of examining into the functions of an organ, closed to most persons, but thus thrown open to him. This task he has performed in a manner highly creditable to his industry and intelligence; and the manner in which he has related his observations and experiments, is such as to carry to every mind a conviction, if not of their absolute truth, certainly of the absence of all intentional error.

It is not our intention to give a detailed account of all the experiments and opinions which are contained in this book. Such a statement belongs appropriately to professional works. There are however many principles and facts in it, of such general importance and application, as to render them interesting to every scientific inquirer. Some of them we propose to lay before our readers, in as condensed a form as is consistent with their intelligibility.

Nearly one half of the book is occupied with preliminary observations, arranged under the following heads: 1st, Of Aliment. 2d, Of Hunger and Thirst. 3d, Of Satisfaction and Satiety. 4th, Of Mastication, Insalivation and Deglution. 5th, Of Digestion by the Gastric Juice. 6th, Of the appearance of the Villous Coat, and of the Motions of the Stomach. 7th, Of Chylification, and of the Uses

of the Bile and Pancreatic Juice. The remainder consists of four series of experiments upon various points connected with the appearance, temperature, motions, and secretions of the stomach, and with the changes which aliment undergoes when submitted to its action, amounting in the whole to almost two hundred and fifty, each of which occupied in its performance several hours, and many of them several days.

The course which we shall adopt, is to state in the form of distinct propositions, without much regard to the order in which they are found in the work itself, a few of the most important principles which it contains, and to accompany them with the facts by which they are supported.

1st. There is a distinct fluid poured into the stomach, possessing peculiar and important properties: this fluid, Dr. Beaumont, following Spallanzani, calls the Gastric Juice.

The proofs of the existence of this fluid are complete. Dr. Beaumont has obtained it, almost in a state of purity, in many hundred instances, by exciting the action of the vessels of the stomach, when empty, and after fasting. His account of the manner of doing it, is this."The usual method of extracting the gastric juice, is by placing the subject on his right side, depressing the valve within the aperture, introducing a gum elastic tube, of the size of a large quill, five or six inches into the stomach, and then turning him upon the left side, until the orifice becomes dependent. In health, and when free from food, the stomach is usually entirely empty, and contracted upon itself. On introducing the tube, the fluid soon begins to flow, first in drops, then in an interrupted, and sometimes in a short continuous stream. Moving the tube about, increases the discharge. The quantity of fluid ordinarily obtained is from four drachms, to one and a half or two ounces. Its extraction is generally attended by that peculiar sensation at the pit of the stomach, termed sinking, with some degree of faintness." P. 21.

The fluid thus obtained he describes as being, "a clear, transparent fluid, inodorous, a little saltish, and very perceptibly acid. Its taste, when applied to the tongue, is similar to that of thin mucilaginous water, slightly acidulated with muriatic acid. It is readily diffusible in water, wine or spirits, and effervesces slightly with carbonated alkalies." P. 85.

No exact chemical analysis of this fluid has been effected. The experiments upon it by Professors Dunglison, Emmett and Silliman,

as stated at p. 78 and 80, warrant the conclusion that it contains, in addition to animal matter soluble in cold, but insoluble in hot water, together with the Phosphates and Muriates of Potassa, Soda, Magnesia and Lime, a considerable amount of free muriatic acid, some acetic and a trace of sulphuric acid.

It is hoped that a more perfect analysis may be obtained from Professor Berzelius, to whom a quantity of it, was sent the last

summer.

The principal properties of this fluid are: it is insusceptible of putrefractive fermentation: it prevents the putrefaction of animal and vegetable substances: it coagulates animal and albuminous fluids and is a perfect solvent of most animal and vegetable substances.

2. The gastric juice is secreted into the stomach only when some foreign body, especially alimentary matters, are brought into contact with its mucous coat. The author's account of this process as well as of the appearance of the villous coat of the stomach is perfectly satisfactory and highly interesting.

"The inner coat of the stomach, in its natural and healthy state, is of a light, or pale pink color, varying in its hues, according to its full or empty state. It is of a soft, or velvet-like appearance, and is constantly covered with a very thin, transparent, viscid mucus, lining the whole interior of the organ.

"Immediately beneath the mucous coat, and apparently incorporated with the villous membrane, appear small, spheroidal, or oval shaped, glandular bodies, from which the mucous fluid appears to be secreted.

"By applying aliment, or other irritants, to the internal coat of the stomach, and observing the effect through a magnifying glass, innumerable minute lucid points, and very fine nervous or vascular papillæ, can be seen arising from the villous membrane, and protruding through the mucous coat, from which distills a pure, limpid, colorless, slightly viscid fluid. This fluid, thus excited, is invariably distinctly acid. The mucus of the stomach is less fluid, more viscid or albuminous, semi-opaque, sometimes a little saltish, and does not possess the slightest character of acidity. On applying the tongue to the mucous coat of the stomach, in its empty, unirritated state, no acid taste can be perceived. When food, or other irritants, have been applied to the villous membrane, and the gastric papillæ excited, the acid taste is immediately perceptible. These papillæ, I am convinced, from observation, form a part of what is called by authors,

the villi of the stomach. Other vessels, perhaps absorbing as well as secretory, compose the remainder. That some portion of the villi form the excretory ducts of the vessels, or glands, I have not the least doubt, from innumerable, ocular examinations of the process of secretion of gastric juice. The invariable effect of applying aliment to the internal, but exposed part of the gastric membrane, when in a healthy condition, has been the exudation of the solvent fluid, from the above mentioned papillæ.-Though the apertures of these vessels could not be seen, even with the assistance of the best microscopes that could be obtained; yet the points from which the fluid issued were clearly indicated by the gradual appearance of innumerable, very fine, lucid specks, rising through the transparent mucous coat, and seeming to burst, and discharge themselves upon the very points of the papillæ, diffusing a limpid, thin fluid over the whole interior gastric surface. This appearance is conspicuous only during alimentation, or chymification. These lucid points, I have no doubt, are the termination of the excretory ducts of the gastric vessels or glands, though the closeset and most accurate observation may never be able to discern their distinct apertures.

"The fluid, so discharged, is absorbed by the aliment in contact, or collects in small drops, and trickles down the sides of the stomach, to the more depending parts, and there mingles with the food, or whatever else may be contained in the gastric cavity.

"The gastric juice never appears to be accumulated in the cavity of the stomach while fasting; and is seldom, if ever, discharged from its proper secerning vessels, except when excited by the natural stimulus of aliment, mechanical irritation of tubes, or other excitants."

This account of the phenomena attending the flow of the gastric fluid into the stomach, explains the fallacious nature of the experiments of Montegre, who could vomit at will, and who after analyzing the fluid so obtained, declared that it was not acid, not slow to putrify, not a solvent, and so much like saliva, that he regards it as saliva swallowed. The fluid which he thus obtained, was probably nothing more than saliva, mingled with the ordinary mucous secretion, of the inner coat of the esophagus and stomach. Received in this light, all the deductions which he drew from his experiments, and which have been considered by some physiologists as so strongly opposed to the chemical nature of the changes which take place in the stomach, loose their whole weight. The substance which he obtained was