us is very different from that of ordinary schools. We do not regard the acquisition of knowledge as an end, but as a means to the mental improvement of the pupil. The school-book is a physician's prescription, to be given under his immediate direotion, and results that would be gratifying to him might be far from satisfactory to the professional school-master. The graduates of these crazy schools will doubtless never astonish the world with their learning, nor will the schools themselves ever be models for general imitation; but for the object sought they bid fair to meet the highest anticipations of their friends.

ART. III.-CASE OF RE-AMPUTATION AT THE HIP. BY GEORGE A. OTIS, Assistant Surgeon U. S. A. Abstract from the American Journal of the Medical Sciences.

In the case of a soldier of the 4th artillery, whose left leg was shattered by a large projectile at Deep Bottom, Virginia, August 6th, 1864, and primarily amputated, and re-amputated at the knee August 23d, Dr. Otis re-amputated at the hip on May 25th, 1870, on account of osteomyelitis of the whole of the shaft of the femur. The patient, Julius Fabry, was thirty-eight years of age when remanded. He passed through many perils during his life in hospital, having a ball and fuse-screw extracted from his stump, the protruding condyles of the femur resected, and a bed-sore over the sacrum, which was long in healing. Having been returned to his regimental headquarters in 1865, he suffered from recurring abscesses in his stump; and when his regiment moved from Fort Washington, in 1865, he was discharged from service, and became a pensioner at the Old Soldiers' Home near Washington. For the next five years he had frequent attacks of severe suffering in consequence of the detachment of bits of dead bone and the reformation of abscesses. Constitutional treatment was employed, and efforts

were made to remove the dead bone; but it finally became apparent that necrosis of the femur extended quite up to the trochanters, and that exarticulation was the only remedy. The operation was performed by a long anterior flap-cut from within outwards, and a straight incision posteriorly. This operative method was necessitated by the masses of foliaceous callus on the outer part of the thigh bone, which would not permit of transfixion.

Necrosis of the Left Femur following Amputation for Gunshot Injury of the Leg.-An aortic compress was used, but not advantageously, as it seemed to increase the venous hæmorrhage. There was absolutely no arterial hæmorrhage, the femoral being controlled by Dr. Billings at the crural arch and in the flap, and ligated, and its branches as well, by Drs. Norris and Woodward, almost as soon as the incision was made. The flap readily united, and in twenty-one days the patient was able to be about on crutches. He made a good recovery, and late in December, 1870, was reported to be in excellent health.

After describing the case, the operator gives a resume of the results of previous re-amputations at the hip in civil and military practice, and demonstrates the comparative safety of this operation in suitable cases.

ART. IV.-EFFECTS OF INCREASED ATMOSPHERIC PRESSURE UPON THE HUMAN BODY, with a Report of Thirty-five Cases brought to City Hospital from the Caisson of the St. Louis and Illinois Bridge. By E. A. CLARK, M. D., Professor of Principles of Surgery and Surgical Anatomy in the Missouri Medical College. [Published by request of the St. Louis Medical Society.]

Mr. PRESIDENT,―The members of this Society having, by resolution, requested a detailed report of the cases treated by me at the City Hospital who were effected in working in the compressed air in the caisson of the bridge now being constructed across the Mississippi river at this city, I would submit the following thirty-five cases: Though most of them present, in many respects, a degree of sameness, there is in some of them a contrast in the symptoms and results calculated to confuse any pre-conceived idea we may have had concerning the pathology of the affection. But before venturing to present these cases, I think it proper (for the benefit of those who are not familiar with it) to give a brief description of the manner in which the piers are constructed and the caisson entered at the bridge, which I have illustrated by the wood cut on the following page, showing a section of the pier with its shaft, and caisson at the bottom.

The caison c c, upon which the solid masonry M M rests, is octagonal in shape, 80 feet long, 45 feet wide, and 9 feet high, constructed of heavy boiler iron, like a large box with an open bottom. This caisson, like an immense diving-bell, is sunk to the bottom of the river with its open part down. Once resting upon the sand s, at the bottom of the river, air is forced into the caisson by means of pumps until the atmospheric pressure is sufficient to resist the pressure of the entire volume of water in the river surrounding the caisson, so as to prevent the water entering it at the bottom, where it rests upon the sand; while the compressed air also subserves another purpose—that of assisting to support the column of masonry resting upon the top of the caisson. The amount of atmospheric pressure re

quired for these purposes varies at different times-always increasing, of course, as the work on the masonry progressesbut increased or diminished according to the depth of the water in the river which has to be resisted. At the time the workmen were most affected the caisson was resting upon the rock at a depth of 95 feet, the pressure averaging from forty-five to

fifty pounds to the square inch. It is in this compressed atmosphere that the workmen have to labor at digging up the sand and "puddling" it preparatory to pumping it out by large sandpumps, thus allowing the caisson to sink in the sand as the weight of stone is increased upon the top of the pier, which is always above the water. Through the centre of the pier

there is an open shaft ten feet in diameter with a circular stairway, A, landing at the bottom of the caisson, which is entered through the air-lock B, which is an iron box six feet square, in the following manner: On reaching the bottom of the stairway the air-lock is entered through the small door d, which opens inwards. This door is then closed, and the air forced into the lock through the air-valve at i until the pressure is equal to that in the caisson when the door d, communicating between it and the air-lock, swings open, while the entire pressure is then bearing upon the first door entering the air-lock. The manner of coming out is just the reverse of this; on entering the airlock from the caisson the door communicating between them is closed from without, and the air allowed to escape from the "lock" through the valve at e until the pressure is reduced to that of the common atmosphere, when the outside door is opened.

While passing through the air-lock, which requires about five minutes, persons complain of but little inconvenience, except the unpleasant ringing in the ears from the increased pressure upon the tympana. This, however, subsides when the pressure has become equalized, and with but few exceptions the workmen suffer no unpleasant sensations during the two hours they remain in the caisson; but after entering the open air they are attacked in from five minutes to twelve hours with the symptoms detailed in the following cases, for the compiling of which I am indebted to my assistant, Dr. T. A. Arnold:

CASE I.

William C., aged thirty-six years, nativity Ireland, admitted to the hospital February 15th, 1870. Remarkably strong and robust man, and had labored two hours in the caisson of the bridge.

Symptoms.-On leaving the air-chamber was seized with excruciating pain in the head, chest, and extremities, and with hæmoptysis. No paralysis.