Page:Popular Science Monthly Volume 27.djvu/83

Rh sensibility so well defined and persistent as to justify the fourfold division above stated.

We have now to inquire as to the testimony of pathology respecting these motor areas in the brain. Charcot and Pitres, in "Revue Mensuelle," November, 1878, and February, 1879, cite fifty-six cases of brain-dieasesbrain-diseases [sic] bearing on this subject. Twenty-one of these cases show lesions in the brain outside the motor zone, and unaccompanied by motor trouble. Charcot's deductions from these cases are that "there exist in the cortex of the cerebrum tracts which are independent of voluntary motion, and when lesions occur in these tracts there are no permanent affections of the motor functions." The remaining cases cited by Charcot show lesions in the motor zone, and are accompanied by varied degrees of paralysis in keeping with the situation and extent of the lesion. Dr. Bechstrew, in the "Medicinische Wochenschrift," St. Petersburg, details a number of cases which confirm the recent views on the motor functions of the areas about the middle convolutions. Other confirmatory cases have been cited by Burdon and Maragliano, by Dr. Henry Obersteiner, and many more. It is well known, however, that a number of opposing instances are on record—that is, of lesions in the so-called motor zone without paralysis, and of paralysis unaccompanied by lesions in these portions of the brain. There is a fundamental objection to this kind of evidence: it is selected evidence, chosen to make for or against a theory. What we really need is a collection of all cases of injuries to parts of the hemispheres, and a full statement of consequences without regard to the bearing of the example.

This is the proper place to mention a brain disorder more or less commonly known under the name of aphasia. Aphasia is a disturbance of the power of speech. It appears in two distinct forms, viz., amnesic and ataxic aphasia. The person suffering from amnesic aphasia forgets substantives and names, other parts of speech being properly used; or he forgets a language which he once knew, or he misapplies terms, "using pamphlet for camphor, horse for man," etc. In ataxic aphasia the power of articulation is completely lost. The person understands fully the word to be used, and makes vigorous effort to use it, but is unable to do so. Sometimes articulation is half destroyed, so that the first part of the word can be spoken, but not the other. Sometimes automatic phrases can be uttered, such as yes and no, while it is perfectly clear that these exclamations do not satisfy the person. Another form of this general trouble is agraphia, or the inability to express ideas in writing; this is frequently complete, and all attempts at writing end in a scrawl. It is noticeable that aphasia is sometimes, though seldom, unaccompanied by insanity. As early as 1861 Broca, in Paris, expressed the opinion that aphasia was connected with disease in the third frontal convolution. While a large number of cases have been cited for and against this conclusion,