Lectures on giddiness and on hysteria in the male.

  • Stewart, Thomas Grainger, Sir.
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: Lectures on giddiness and on hysteria in the male. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    interesting account of some experiments which he had made upon the subject. He pointed out that if the body be passively rotated, one can, witli the eyes bandaged, determine pretty accurately the amount of movement made; that if such passive movements be continued beyond a certain time, the feeling is lost, but that if the rotation be suddenly arrested, the sensation of rotation continues. He suggested the theory that the sensations are due to alterations of pressure in the endolymph, not from mere gravitation, as had been supposed, but from the formation of currents (or, more strictly s]Deaking, the production of a strain) in the endolymph, that fluid being conceived to lag behind in the rotational movement of the head. He pointed out how well such a theory suffices to explain the facts discovered by himself, as well as those previously known. Moreover, he remarked, that as each canal has but one ampulla, and as the same organ of sense can produce sensations differing in quantity only, and not in quality, it is probable that one canal will respond only to the rotation round one axis, and in one direction, because the sensation of rotation in the opposite direction is qualitatively different. Hence he concluded that the semicircular canals are paired organs, and that each canal corresponds only to rotation in a single direction. The same theory was promulgated independently, and at about the same time, by Professors Mach of Prague and Breuer of Vienna. Some later experiments of Cyon throw doubt upon this kinetic theory, but cannot be held, in my opinion, to have disproved its principle. You perceive, then, that we have abundant proof that the semicircular canals are sensory organs subserv- ing equilibration, and that we are gradually acquiring definite ideas as to how their functions are performed.