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Page:Popular Science Monthly Volume 7.djvu/484

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THE POPULAR SCIENCE MONTHLY.

going from the periphery of the convolutions to the central gray column. The nervous influx first goes into those two large ganglions of gray substance, the corpora striata and the optic layers. Probably these organs transform the phrase thought into voluntary movement. From the corpora striata the vibration is transmitted along the central axis to the olivary bodies, which are the coördinating apparatus, and which regulate and direct the movement. From the olivary bodies proceed nerves to the lips, the larynx, the tongue, the pharynx, the palate—all the vocal organs concerned in production of language. Pathological facts teach us that these different apparatuses may be destroyed separately, and there is then involved the absolute loss of such and such a function.

Thus in a case recorded by Dr. Winslow, the man had retained the faculty of language; he could write the words and phrases which he thought of; but, when he tried to speak, he only uttered confused sounds. In this instance the olivary bodies were alone affected. The faculty of language remained intact; the vocal apparatus was not injured; but the apparatus of transmission was profoundly altered.

In other cases, again, it is the organ of thought itself that is diseased. There is an affection well known to physicians who study the insane, and which is called general paralysis. This disease begins in the periphery of the convolutions, which are devoured (so to speak) by a slow inflammation characterized by intermittent extensions. One may take account of the disorders it causes by the state of intelligence of the patients. At first the inflammation produces an intellectual excitation, which expresses itself in mad acts. Each time a fresh access of madness is observed, one may pretty surely infer a new extension of the disease. But at length, when the whole outer surface of the hemispheres is destroyed, there is no longer either thought, or will, or instinct; the unhappy subjects are plunged in a state of somnolence and stupor, from which nothing can rouse them. They do not speak, because the organ of thought no longer exists.

It is probable, then, that between the organ of thought and the vocal organ there is a third organ—the organ of words, and it is a lesion of this which properly constitutes aphasia.—English Mechanic.

 

ARCTIC ICE-TRAVELS.
By CLEMENTS R. MARKHAM, F. R. S.

FORMERLY exploration in the arctic regions was entirely performed by ships. On one or two occasions only were sledge-parties dispatched for the purpose of discovery, and then on a very reduced scale. During the search expeditions, however, after Sir John Franklin and his gallant companions, the system of sledge-trav-