Operations on the kidney are among the most remarkable triumphs of abdominal surgery. In 1869 Simon, of Heidelberg, had a patient suffering from various troubles with the duct of the kidney. After many experiments on dogs to determine whether it was possible for them to live with one kidney, after the sudden removal of its fellow, he ventured to remove this otherwise healthy organ, and the patient lived for eight years in perfect health. Since then very many such operations have been done, and the latest results are as follows: In 375 cases of entire removal of one kidney in consequence of its being hopelessly diseased, 197 lives were saved. In 95 cases of abscesses and other diseases, in which the kidney was cut down upon in the loin or abdomen, and the kidney opened and drained, 76 lives were saved. In 102 cases in which stones were removed from the kidney, 76 lives were saved, and in 25 cases in which the kidney (as in the case of the spleen above referred to) was "floating" around loose in the abdomen, and a source of discomfort and pain, it had been cut down upon, sewed fast in its proper place, and all but one got well, and even this one death was from injudicious surgery. A total of 597 operations on the kidney shows, therefore, recovery and in general complete restoration to health in 373. Had the patients been let alone (as they would have been prior to Simon 's experiments in 1869), almost every one would have died, and that too after weeks, or years it might be, of horrible pain and loathsome disease.

But the most extraordinary achievement of modern surgery remains to be told. In the "Lancet" for December 20, 1884, Dr. Bennett and Mr. Godlee published an article which startled the surgical world. Dr. Bennett had diagnosticated not only the existence, but the exact locality of a tumor in the brain, of which not the least visible evidence existed on the exterior of the skull, and asked Mr. Godlee to attempt its removal. The head was opened and the brain exposed.

No tumor was seen, but so certain were they of the diagnosis that Mr. Godlee boldly cut open the healthy brain and discovered a tumor the size of a walnut and removed it. After doing well for three weeks, inflammation set in, and the patient died on the twenty-sixth day. But, like the failure of the first Atlantic cable, it pointed the way to success, and now there have been 20 tumors removed from the brain, of which 17 have been removed from the cerebrum with 13 recoveries, and 3 from the more dangerous region of the cerebellum, all of which proved fatal. Until this recent innovation every case of tumor of the brain was absolutely hopeless. The size of the tumors successfully removed has added to the astonishment with which surgeons view the fact of their ability to remove them at all. Tumors measuring as much as three and four inches in diameter and weighing from a quarter to over a third of a pound have been removed and the patients have recovered.

Another disease formerly almost invariably fatal is abscess of the brain. In the majority of cases this comes as a result of long-standing disease of the ear, which after a while, involves the bone and finally the brain. So long ago as 1879 Dr. Macewen, of Glasgow, diagnosticated an abscess in the brain, and wished to operate upon it. The parents declined the operation, and the patient died. After death Macewen operated precisely as he would have done during life, found the abscess and evacuated the pus, thus showing how he could probably have saved the child's life. Since then the cases treated in such a manner amount to scores, and more than half of them have recovered without a bad symptom.

In injuries of the skull involving the brain, the larger arteries are sometimes wounded, and the blood that is poured out between the skull and the brain produces such pressure as to be speedily fatal. In some cases, even without any wound, the larger arteries are ruptured by a blow or fall, and a similar result follows the hæmorrhage. Nowadays, in both of these injuries, any well-instructed surgeon will open the head, secure the bleeding vessel, and turn out the clot with a good chance of recovery in a large number of cases. Even gunshot wounds of the brain are no longer necessarily fatal. Among a number of other successful cases one has been recently reported in which the ball went all the way from the forehead to the back of the head, and after striking the bone rebounded into the brain. The back of the skull was opened, the ball removed, and a rubber drainage tube of the calibre of a leadpencil passed in the track of the ball completely through the head, and the patient recovered. So little danger now attaches to opening the skull, with antiseptic precautions similar to those already described, that the latest writer on trephining (Seydel) estimates that trephining per se is fatal only in 1.6 per cent. of the cases. Mr. Horsley has recently published a most remarkable paper, including 10 operations on the brain, in which, without anything on the exterior to indicate its situation, the site of the disease was correctly located in all, and 9 of them recovered after operation.

Almost equally astonishing are the results of brain surgery in certain cases of epilepsy; for the surgical treatment of the cases justifying such interference has been attended with the most brilliant results. In these cases the spasm begins in a particular part of the body; for example, the hand or the thumb, or it is limited to one arm, or to one side of the body. Some of them have been operated upon without any benefit, but a large number of other cases have been operated on and either benefited or, in not a few cases, have been completely restored to health. That the words "brilliant results" are not inappropriate will certainly be granted when we look at Mr. Horsley's table of cases. One patient had 2870 epileptic convulsions in thirteen days, and completely recovered, not only from the operation, but also from his terrible malady, after the removal of a diseased portion of the brain, the result of an old depressed fracture of the skull. Besides this, a few cases of headache so inveterate as to make ordinary occupations impossible and life itself a burden have been cured by trephining the skull. Even insanity itself has been cured by such an operation in cases in which it has followed injuries to the head. What the ultimate result of these recently inaugurated operations will be it is impossible to tell as yet, but thus far they have been so beneficent and so wonderful as to arouse not only our greatest astonishment, but also our most sanguine hopes.

The question will naturally arise how is it that the neurologists can determine so exactly the location of such tumors, abscesses, hæmorrhages, scars, and other alterations of tissue giving rise to epilepsy and other disorders mentioned, without the slightest indication on the exterior of the skull to point to the diseased spot. That this is of supreme importance in the brain will be evident upon a moment's reflection. In other parts of the body, even if we make an error of an inch or two, it is of comparatively little importance, as the incision can be easily prolonged, and heals readily. But in the skull, from the very nature of the bony envelope, an error of an inch or two means almost certain failure to find the disease, and means, therefore, possibly the death of the patient.

It is impossible within the limit of this paper to state in detail the method, but the following brief sketch may give some idea of it. Whatever can be advanced against vivisection, there is this to be said in its favor, that without it the exact localization of cerebral tumors and other such lesions, which is one of the chief glories of the present day, would be impossible. We owe our knowledge of the location of cerebral functions to many observers, chief of whom are Ferrier and Horsley, of England, and Fritsch, Hitzig, and Goltz, of Germany. Horsley's method will suffice as a type. The brain of a monkey having been exposed at the part to be investigated, the poles of a battery are applied over squares one-twelfth of an inch in diameter, and all the various movements which occur (if any) are minutely studied. One square having been studied, the next is stimulated, and the results are again noted, and so on from square to square. These movements are then tabulated. For example, all those adjacent squares which, when stimulated, produce movements of the thumb are called the region for representation of the thumb, or, shortly, "the thumb centre"; and to all those squares which produce movements of the hand, the elbow, the shoulder, or the face, etc., are given corresponding names. In this way the brain has been mapped out, region by region, and the same minute, patient study given to each.

These animals, I should add, are etherized so that they do not suffer the least pain. I may also say in passing that such operations, with few exceptions, even without ether, are not painful. The brain itself can be handled, compressed cut, or torn without the least pain. A number of cases have already been reported in which a considerable portion of the human brain has been removed by operation and the patients have been out on the street within a week, without pain, fever, or a single dose of medicine.

Studying in this way the brain of the lower animals, we now have a very fair knowledge of the localization of many of its functions. With the functions of the front part we are as yet not familiar. The part which lies, roughly speaking, behind and in front of one of the chief fissures of the brain (the fissure of Rolando), which runs downward and forward above the ear, is known as the motor region." In this region the different centres have been mapped out in the monkey's brain, and have been verified in the brain of man many times. Most of that part of the brain above and behind the ear has no special functions that we know of at