It is rarely, indeed, that we can actually see what is going on in a healthy stomach; but in a few instances this advantage has been enjoyed, and turned to account in investigating the phenomena of digestion. By far the most instructive example of this kind which has ever occurred, came under the observation of Dr Beaumont of the American army; and, as that gentleman eagerly embraced the opportunity so unexpectedly afforded him, of testing the prevailing doctrines by a series of experiments, continued during a period of several years, and under various conditions of health and external circumstances, I shall so frequently have occasion to refer to his observations, that it will be useful to give a brief outline of the case before entering farther upon the subject, in order that the reader may be enabled to judge for himself what weight is due to Dr Beaumont’s evidence on any disputed point.
Dr Beaumont, while stationed at Michillimackinac in the Michigan territory in 1822, in the military service of the United States, was called upon to take charge of Alexis St Martin, a young Canadian of eighteen years of age, good constitution, and robust health, who was accidentally wounded by the discharge of a musket on 6th June 1822.
“The charge,” says Dr Beaumont, “consisting of powder and duck-shot, was received in the left side, at the distance of one yard from the muzzel of the gun. The contents entered posteriorly, and in an oblique direction, forward and inward; literally blowing off integuments and muscles to 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 lobe of the lungs, the diaphragm, and PERFORATING THE STOMACH.”
On the fifth day, sloughing took place; lacerated portions of the lung and stomach separated, and left a perforation into the latter, “large enough to admit the whole length of the middle finger into its cavity; and also a passage into the chest half as large as his fist.” Violent fever and farther sloughing ensued; and for seventeen days every thing swallowed passed out through the wound, and the patient was kept alive chiefly by nourishing injections. By-and-by the fever subsided, the wound improved in appearance, and after the fourth week the appetite became good, digestion regular, the evacuations natural, and the health of the system complete. The orifice, however, never closed; and at every dressing the contents of the stomach flowed out, and its coats frequently became everted or protruded so far as to equal in size a hen’s egg, but they were always easily returned. The prefixed figure exhibits the appearance of the wound after it was healed. The circumference of the wound EEEL, extended to about twelve inches; and the opening into the stomach AAA, nearly in its centre, was about two inches below the left nipple F. The folds of the villous coat are visible at BC.
Some months after, St Martin suffered extremely from the death and exfoliation of portions of the injured ribs and their cartilages, and his life was often in jeopardy; but through the skill and unremitting care with which he was treated by Dr Beaumont, he ultimately recovered, and, in April 1823, was going about, doing light work and rapidly regaining strength.
On 6th June 1823, a year from the date of the accident, the injured parts were all sound, except the perforation into the stomach, which was now two and a-half inches in circumference. For some months thereafter the food could be retained only by constantly wearing a compress and bandage; but early in winter, a small fold or doubling of the villous coat began to appear, which gradually increased till it filled the aperture and acted as a valve, so as completely to prevent any efflux from within, but to admit of being easily pushed back by the finger from without.
Here, then, was an admirable opportunity for experimenting on the subject of digestion, and for observing the healthy and undisturbed operations of nature free from the agony of vivisections, and from the sources of fallacy inseparable from operating on animals. Dr Beaumont was sensible of its value, and accordingly pursued his inquiries with the most praiseworthy perseverance, and disinterestedness. Having been fortunate enough to obtain a copy of his work, I shall not hesitate to make free use of its contents.
Dr Beaumont began his experiments in May 1825, and continued them for four or five months, St Martin being then in high health. In the autumn, St Martin returned to Canada, married, had a family, worked hard, engaged as a voyageur with the Hudson’s Bay Fur Company, remained there four years, and was then engaged at a great expense by Dr Beaumont to come and reside near him on the Mississippi, for the purpose of enabling him to complete his investigations. He came accordingly in August 1829, and remained till March 1831. He then went a second time to Canada, but returned to Dr Beaumont in November 1832, when the experiments were once more resumed, and continued till March 1833, at which time he finally left Dr Beaumont. He now enjoys perfect health, but the orifice made by the wound remains in the same state as in 1824.
Dr Beaumont describes the aperture in St Martin’s stomach as being situated about three inches to the left of the cardia, near the left or superior termination of the great curvature. When the stomach was nearly empty, he was able to examine its cavity to the depth of five or six inches by artificial distention. When it was entirely empty, the stomach was always contracted on itself, and the valve generally forced through the orifice, together with a portion of the mucous membrane equal in bulk to a hen’s egg. After sleeping for a few hours on the left side, the protruded portion became so much larger, as to spread “over the neighbouring integuments five or six inches in circumference, fairly exhibiting the natural rugæ, villous membrane, and mucous coat, lining the gastric cavity. This appearance is almost invariably exhibited in the morning before rising from bed.” Such was the very favourable subject on whom Dr Beaumont’s observations and experiments were made, and such were the numerous opportunities which he enjoyed for repeating them, and verifying their accuracy. Having given this outline, we now return to the consideration of the gastric juice, on the origin and qualities of which it removes any uncertainty which previously existed.