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

present, except one region, which is the centre for sight. Injury to this produces blindness of the half of each retina on the same side as the injury to the brain. But it is extremely difficult to obtain in the lower animals any evidence of the special senses other than that of touch, the abolition of which produces loss of feeling, of which we can get exact evidence. Motion and sensation, therefore, are the two things that can be most readily determined.

Having now ascertained in animals the location of the particular centres, the next step is to apply this knowledge to the human brain in judging of the processes of disease. But it will be easily seen that the experiments that disease performs in a human brain are clumsy, spread over a wide area, and therefore often difficult of interpretation. Instances affecting a single little area of brain surface one-twelfth of an inch in diameter are almost unknown, and a tumor has been removed of such size that it produced direct pressure upon more than twelve hundred such squares, and indirectly produced pressure upon many distant parts of the brain. This is, of course, very clumsy experimentation. The familiar game of "shouting proverbs" will well illustrate the difficulty of interpreting the answers of disease to our question, "Where is it located?" Imagine 1200 persons, each assigned a single word of a proverb of 1200 words. At a given signal each shouts his own word. What a Babel of sound! How utterly impossible of disentanglement and proper arrangement! This is the answer of disease as represented by such a tumor. Take each of the 1200 persons in the proper order and question him separately and repeatedly, write down the answers accurately and in their proper sequence, and behold the proverb! This is the answer of scientific investigation as seen in vivisection.

Instead of there being a tumor, a blood-vessel will sometimes break in the brain, and produce a clot, affecting similarly

a large area; or softening of the brain will in the same way invade an equal or a greater number of centres. It is therefore extremely rare that we can find a small area, such as that for speech, or for the hand, or for the arm, or for the face, or for the leg, or for sight, that is involved entirely by itself. But such cases do occasionally occur, and they are extremely valuable in fortifying the conclusions derived from the exact experiments of the laboratory. While some of the cases have introduced confusion and uncertainty from the character of nature's experiments, it can be broadly asserted that generally they have absolutely confirmed them. The results obtained by the surgery of the brain have more than confirmed them; for, as indicated already, the brain has been opened, and that portion which, according to experiment, is believed to be the centre for the wrist, or for the shoulder, etc., has been cut out, and paralysis of the corresponding part (a paralysis which, however, is only temporary) has proved positively the exactness of the inference from animals.

We are still a little uncertain as to the exact functions of large portions of the brain, but we have made a reasonable beginning; we have found firm ground to stand upon, and the results already obtained in the relief of human suffering and the cure of disease are such as readily encourage the hope that in the near future we shall be able to do vastly more. The opponents of vivisection have stoutly contended that it has shown no useful results. Let us wholly ignore the researches of Sir Charles Bell, of Harvey or Hunter, or other experimenters of the past. Here is a field in which the last ten years have opened wholly new ground for modern surgery, in which already the operations of the last four years have been marvellously successful, and have startled even surgeons themselves. Had vivisection done nothing else than this, it would be amply justified, and to obstruct re

searches so rich in beneficent results would be a disaster to humanity.*

But not only has the brain been opened and compelled to give up its secrets, and to yield itself to the successful assaults of the surgeon, but the spine has also of late been the field of some remarkable work. About a year ago Mr. Horsley reported a remarkable case, in which a tumor by pressure on the spinal cord had been the source of most frightful pain for a long time, and of paralysis of all the lower half of the body. Once that an accurate diagnosis, not only of its existence, but of its actual locality, was made, he made an incision in the back, exposing the backbone, cut away the bone down to the membrane, and even to the spinal marrow itself, and removed the tumor. When last reported the patient was able to walk three miles, and even to dance. Since then there have been numerous successful operations upon the spine in this country, in England, and in France, and the near future will doubtless show even better results. Already severe fractures of the spine have been operated upon by removal of the fragments sticking into the spinal marrow, and recovery has followed instead of a lingering and certain death.

We are only just beginning to interfere surgically with the lungs; to open abscesses in them, and to remove por

*The facts stated in this paper, it seems to me, are a striking vindication of the value and necessity of vivisection. Personally I have never done any such experiments, save a few some twenty years ago. Indiscriminate experimentation by untrained students I would heartily discourage, as they would lead to no good results. But as a matter of fact such indiscriminate experiments by students do not exist. They have neither the time, the money, nor the facilities for it. Only competently trained men who will make a serious and systematic investigation of definite problems, and educe the knowledge that will widen our scientific horizon and enlarge our resources in the healing art, should engage in it, and as a fact I believe only such do engage in it. Moreover, they ought to, and, so far as my knowledge extends, they do inflict no needless pain.

tions successfully; and several ribs have been removed in cases of chronic pleurisy and deformed chests.

Formerly one of the most dangerous operations known was the removal of goitres. Hæmorrhage, inflammation, and blood-poisoning destroyed a very large number of such cases, and when Kocher, of Berne, in 1882, reported 58 operations, with a mortality of only 14.3 per cent., it was deemed a triumph. But improved methods of operation reduced the mortality until, in 1884, he reported 43 more operations, with a mortality of only 6.9 per cent., and in 1889 he has just reported 250 additional operations, and all but 6 patients recovered-a mortality of but 2.4 per cent., or, if we exclude the 25 cases of cancer, which gave 4 of the deaths, we have 225 cases and only 2 deaths, a mortality of but 0.8 per cent.

We see few cases of severe knock-knee and bowlegs in this country, but among the ill-fed lower classes of Europe they are common. Formerly almost nothing could be done; but a few years ago surgeons began to operate upon them in this way: A small cut is made through the skin and muscles down to the bone, and by a saw or a chisel the bone is divided. The limb is then straightened, and the case treated precisely as if it were an ordinary fracture. It heals without fever or serious pain, and the patient is well. With modern methods this is not a dangerous operation, as will be seen by the remarkable paper read by Macewen, of Glasgow, at the International Medical Congress of 1884, in Copenhagen, when he reported 1800 operations on 1267 limbs in 704 patients, and only 5 died, in spite of the fact, too, that most of them, from deformity in several limbs, had to have multiple operations. Even these deaths were not due to the operation, but followed from pneumonia, typhoid fever, consumption, and diphtheria.

We have learned, too, that portions of the body can be entirely severed, and, if suitably preserved, can be replaced,