a little acid (hydro-chloric or lactic) is added. When administered in form of powder there will be acid enough in the stomach to dissolve it and make it active; when prescribed in solution a little acid has to be added. For the preparation of liquid pepsin it suits well, and has the advantage that every druggist, who does not like to make it directly from the stomach, can readily make it. For that purpose I propose the following formula: R-Saccharated pepsin, 64 grains; water, 5 fluid ounces; muriatic acid, 1 fluid drachm. Shake in a bottle until the pepsin and milk-sugar are completely dissolved, then add three fluid ounces of glycerine and filter. A colorless liquid is formed, of which one fluid ounce dissolves 1 drachms of coagulated albumen. The strength of the saccharated pepsin, ascertained by its solvent power on coagulated albumen, is, compared with other dry pepsins in use here, such that one part of it equals about 3 parts of Boudault's, 8 to 9 parts of Grimault's, 12 parts of Hawley's, and at least 40 parts of Houghton's dry pepsin.

While 10 grains of saccharated pepsin in one fluid ounce of water acidulated with 10 drops of muriatic acid, and kept at a temperature of 100 to 105° F., dissolved 120 grains of coagulated albumen in from 3 to 4 hours, it required under identical conditions between 30 and 40 grains of Boudault's to dissolve the same amount; 60 grains of Grimault's dissolved but 84 grains, and 60 grains of Hawley's only 60 grains of coagulated albumen. With Houghton's pepsin most of the little cubes, into which the albumen was cut, had not even lost their sharp angles and corners. Boudault's pepsin, which I had used for experiments last winter, must have been adulterated or spoiled, as I recollect right well that it was a damp, sticky powder, of somewhat different color than the one I used this time; therefore its strength compared with the liquid pepsin was found so much less than in the present experiment.

To substantiate the assertion formerly made that wine of pepsin and all other preparations of pepsin containing alcohol were devoid of digestive power, I made the following experi

ments: Two equal quantities of dry pepsin were dissolved in acidulated water, and to one of them after solution of alcohol was added. The same amount of coagulated albumen was put into each bottle. By the time that the albumen in the vial without alcohol was entirely dissolved, the albumen in the other one was not acted upon, and the little cubes had retained their shape.

Dry pepsin, precipitated with alcohol from its solution, was dissolved in acidulated water, and coagulated albumen added to it; a solution of my dry pepsin was likewise made and the same quantity of albumen added. The pepsin made with alcohol did not seem to act on the albumen, which appeared to be exactly the same in shape and bulk as when it was put in, in a certain time by which my pepsin had dissolved the albumen entirely. It seemed to me to be of importance to find if pepsin made from calf rennet was identical with that made from the hog. I therefore prepared a liquid pepsin from rennet in exactly the same way and the same proportions as from the mucous membrane of the hog. When compared with liquid pepsin, as to its digestive strength, it was found that pork pepsin dissolved about more of coagulated albumen than calf pepsin in the same time. With dry pepsin made from rennet I obtained the same result. By experimenting with meat the difference was still more in favor of the pork pepsin, as a certain quantity of beef was dissolved by this, while in the same time the bulk of the beef was not appreciably diminished by the calf pepsin, although it had loosened the fibres and softened the meat.

ECLECTIC DEPARTMENT.

"Carpere et colligere."

ART. I.-ACUPRESSURE,* WITH SOME REFERENCE TO ITS APPLICATION IN THE CONTINUITY OF ARTERIES. BY GEORGE A. PETERS, M. D., New York, Attending Surgeon New York Hospital.

Hæmorrhage, with its attendant dangers, was held in such dread by surgeons until a comparatively moderate date that they hesitated long before performing amputation or any important operation which, by the division of large arteries, should induce it. Waiting the time when the process of gangrene and sloughing had obliterated the vessels, they merely lopped off the dead tissue, and left the wound to Nature or to the rude dressings of the day. If others, bolder than their fellows, dared to cut before this time, their chief reliance for checking the flow of blood was upon glowing steel and boiling pitch.

When (three hundred years ago) Ambroise Pare, as he claimed under the inspiration of the Deity, employed and urged upon the attention of the profession the use of the ligature before but hinted at, as it were, he conferred a great boon upon suffering humanity, and robbed surgery of half its terrors to the surgeon. It remained for an American, in the nineteenth century, by the introduction of the inhalation of anæsthetic vapors, thereby obliterating all sensibility to pain, to re pay the debt which our day owed to the past-to make formida ble operations pleasant to the surgeon, painless to the patient, and more certain in their results.

From the time of Pare the ligature continued to grow in

* This paper was read before the Medical Society of the county of New York.

favor, and soon became the sole reliance in stopping the flow of blood after amputation and all major operations. The profession seemed to have settled down in the belief that notwithstanding its few obvious evils, there was, and probably would be, no better means devised. However, Sir James Y. Simpson-believing that, “as a practical science, surgery must ever march onward, it can acknoweldge no boundary to its onward progress and development, and knows no finality "—first described to the Royal Society of Edinburgh at their meeting on the 19th of December, 1859, "acupressure as a new hæmostatic process founded on the principle of the temporary metallic compression of arteries." The proposition was kindly received by the profession, and the method tried by surgeons in various parts of the world. Professor Simpson himself gave the matter no further consideration, as "the subject lay somewhat without the ordinary walks of his study and practice," until December, 1863, when he published in the London Medical Times one or two lectures on acupressure, which have since been enlarged, and have appeared in book form. From time to time cases in which acupressure has been used have been reported in the various medical journals, and remarks made thereon.

Next to Professor Simpson's book, the most complete and satisfactory resume is the joint work on acupressure by Drs. Pirrie and Keith, two surgeons of Aberdeen Scotland, who have recorded a large number of cases, instituted valuable improvements in the methods of its application, and given many hints in its practice.

The essay prepared by Dr. Joseph C. Hutchison, of Brooklyn, L. I., entitled "A Practical Treatise on Acupressure," and read before the Medical Society of the State of New York at their meeting in 1869, to which the "cash prize" was awarded, is by far the most complete and laborious record of acupressure made in this country. By the kindness of Dr. Hutchison I am permitted to avail myself of the results of his experiments on the lower animals and various other matters connected with the subject.

Before proceeding to discuss the various methods by which hæmorrhage from bleeding vessels is checked, it will be well to allude briefly to the anatomical construction of an arterial tube. The walls of arteries are divisible into three coats: The inner one, thin, transparent, and smooth, resembling somewhat a serous membrane. The middle coat, the thickest of the three, is divided into two layers-the outer of the two is yellow elastic tissue, the inner layer is composed of organic muscular fibre arranged circularly; these circular fibres are loosely bound together by connective tissue, and give way easily to a slight degree of force exerted in the circumference of the artery. The outer coat is white, dense, and very elastic, not readily yielding. to force. Arteries are themselves supplied with arteries, veins, nerves, and absorbents, and are thus enabled to undergo any change to which other living tissues are subject, and can inflame and repair.

Let us now briefly consider the means which Nature employs for the suppression of hæmorrhage from divided arteries.

Dr. J. F. D. Jones, an English surgeon, instituted a series of experiments on the lower animals to determine the manner in which hæmorrhage was checked by Nature and by the ligature. The result of these experiments was first made public in a volume published in London in the year 1805, which established these facts, viz: When an artery is divided, we have, first, a spirt of blood; then quickly following this a retraction of the artery within its sheath, and a contraction of its extremity. As the connective tissue between the vessel and its sheath is very loose, it is readily stretched and torn, leaving the internal surface of the sheath uneven; the blood becomes entangled as it flows, and "thus the foundation is laid for the formation of a coagulum at the mouth of the artery, and which appears to be completed by the blood, as it passes through this canal of the sheath, gradually adhering and coagulating around its internal surface till it completely fills it up from the circumference to the centre." This forms the external coagulum, and it is the first complete obstacle to the continuation of bleeding.