Page:Popular Science Monthly Volume 25.djvu/630

614 be true—the one to which the anatomical arrangement and the physiological experiments point—that each part of the brain has its own work to do, a limited area of disease will interfere with the work of the part diseased—will produce a loss or impairment of one function, and will not affect all the powers.

The following instance shows that pathology supports anatomy and physiology, and that the localization of functions and memories is no longer a matter of question among scientists:

Not long ago a man was brought into Bellevue Hospital, in this city, suffering from fever, headache, delirium, and stupor, which had developed after a blow upon the head. In addition to these symptoms, he had a paralysis of the muscles on the back of the fore-arm, so that he could not raise his left hand. The general symptoms indicated the presence of an abscess in the brain. To the surgeon, familiar with the anatomy and with the physiological experiments upon animals, the paralysis of the arm-muscles indicated that the abscess was situated in that part of the brain whose function it was to raise the hand. He therefore sawed through the skull over the supposed site of the abscess, and, although the hole which he made was only large enough to admit his little finger, the abscess was found lying just beneath it, and was emptied.

Such a case shows that the study of localization may aid in saving life. The following cases of loss of a definite kind of memory, occurring suddenly, and accompanied by symptoms which indicated the situation of the disease in the brain, remind one very forcibly of the physiological experiments described, and afford positive proof that powers of sensation and memory, as well as the power of motion, may depend upon the integrity of definite regions of the brain:

An intelligent gentleman, while playing billiards, suddenly became aware of the fact that he could see but one half of the ball at which he was aiming. He had become blind in the right half of both eyes. Soon after, on attempting to read, he found, much to his surprise, that he could not read. He could see the letters and words, but they conveyed no meaning to his mind, and appeared to him as so many forms—just as a set of Chinese letters do to us. He had lost the power to recognize written and printed language. Singularly enough, he could write as well as ever, but it was impossible for him to read what he had just written. The memory of the motion involved in producing a letter remained, the memory of its appearance was gone. The memory of the motion served to take the place to some degree of the lost memory-pictures, for, when asked to read a word, he would bring up his hand to the page and with his finger trace the form of the letter, and then name it. It was evident that the only means he had of recalling a letter was by going through the motion necessary to write it—in other words, by calling into play his motor-memories. As he was more accustomed to trace written than printed letters, it took him a