Open main menu

Page:Popular Science Monthly Volume 18.djvu/123

This page has been validated.

however, the above results were equivocal, catalepsy occurring on the same side as the stroking, or sometimes on one side and sometimes on the other. In all cases of unilateral hypnotism, the side affected as to motion is also affected as to sensation. Sense of temperature under these circumstances remains intact long after sense of touch has been abolished. As regards special sensation, the eye on the hypnotized side is affected both as to its mechanism of accommodation and its sense of color. While color-blind to "objective colors," the hypnotized eye will see "subjective colors" when it is gently pressed and the pressure suddenly removed. Moreover, if a dose of atropine be administered to it, and if it be then from time to time hypnotized while the drug is gradually developing its influence, the color-sense will be found to be undergoing a gradual change. In the first stage yellow appears gray with a bluish tinge, in the second stage pure blue, in the third blue with a yellowish tinge, and in the fourth yellow with a light bluish tinge. The research concludes with some experiments which show that in partly hypnotized persons imitative movements take place involuntarily, and persist until interrupted by a direct effort of the will. From this fact Heidenhain infers that the imitative movements which occur in the more profound stages of hypnotism are purely automatic, or involuntary.

In concluding this brief sketch of Heidenhain's interesting results, it is desirable to add that in most of them he has been anticipated by the experiments of Braid. Braid's book is now out of print, and, as it is not once alluded to by Heidenhain, we must fairly suppose that he has not read it. But we should be doing scant justice to this book if we said merely that it anticipated nearly all the observations above mentioned. It has done much more than this. In the vast number of careful experiments which it records—all undertaken and prosecuted in a manner strictly scientific—it carried the inquiry into various provinces which have not been entered by Heidenhain. Many of the facts which that inquiry yielded appear, a priori, to be almost incredible; but, as their painstaking investigator has had every one of his results confirmed by Heidenhain so far as the latter physiologist has prosecuted his researches, it is but fair to conclude that the hitherto unconfirmed observations deserve to be repeated. No one can read Braid's work without being impressed by the care and candor with which, amid violent opposition from all quarters, his investigations were pursued; and now, when, after a lapse of nearly forty years, his results are beginning to receive the confirmation which they deserve, the physiologists who yield it ought not to forget the credit that is due to the earliest, the most laborious, and the hitherto most extensive investigator of the phenomena of what he called hypnotism.—Nineteenth Century.