Page:Popular Science Monthly Volume 41.djvu/795

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LANGUAGE AND BRAIN DISEASE.
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wholly constructed of wood. Stone was feared, owing to the chances of earthquakes. While there, I visited the church of St. Francis, built of adobes a century before, and it had stood firm and secure all that time. It occurs to me—but I have no right to speak as an expert—that a house built of thick mud walls and wooden joists and rafters would be tolerably safe during an earthquake, unless it was a very severe shock; such a house would also be safer than a wooden one from fire, which has always been a great danger in San Francisco.

LANGUAGE AND BRAIN DISEASE.

By HOWELL T. PERSHING, M. Sc., M. D.

NOTWITHSTANDING the great number of persons engaged in learning and teaching languages, there is no general agreement as to what is the best method that can be employed. Indeed, there seems to be no belief that there can be one method which is best for both modern and ancient languages, for the pupil who must learn to converse and for him who wishes only to read. Nevertheless, there are well-ascertained facts concerning the brain, which point unmistakably to one method as the best. Hence, I have ventured to believe that all engaged in linguistic work would find it interesting and profitable to consider these facts, which, though far outside the linguist's usual field, are capable of throwing a strong light upon his work.

All the motions and sensations of the various parts of the body are represented on the surface of the brain as on a map. Thus, there is a separate brain area necessary for sight, another for hearing, another for the motions of the fingers, and so on. Each of these areas is called a center. Four of these are especially concerned in the use of language, and may therefore be called language centers: the auditory center, by which words are heard; the motor speech center, which excites and controls the vocal organs in speaking; the visual center, by which written words are seen; and the writing center, which guides the motions of the hand in writing. These centers are capable of individual development by practice, and, in order that each one may receive its due share of cultivation, it is necessary to know its relative importance in the different ways of using language.

Disease instructs us on this point by making some interesting though ruthless experiments. Inflammation, or the growth of a tumor, or the rupture or plugging of a blood-vessel, may destroy any of these centers, involving, of course, a loss of the corresponding function. Consequently, the various defects in the