Hume, with Helps to the study of Berkeley : essays / by Thomas H. Huxley.

  • Huxley, Thomas Henry, 1825-1895.
Date:
1894
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Licence: Public Domain Mark

Credit: Hume, with Helps to the study of Berkeley : essays / by Thomas H. Huxley. Source: Wellcome Collection.

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    the olfactory membrane offers, that we must seek for the seat of the organ of the olfactory sense. The only essential part of that organ consists of a multitude of minute rod-like bodies, set perpen- dicularly to the surface of the membrane, and forming a part of the cellular coat, or epithelium, which covers the olfactory membrane, as the epidermis covers the skin. In the case of the olfactory sense, there can be no doubt that the Democritic hypothesis, at any rate for such odorous substances as musk, has a good founda- tion. Infinitesimal particles of musk fly off from the surface of the odorous body; these, becoming diffused through the air, are carried into the nasal passages, and thence into the olfactory chambers, where they come into contact with the filamen- tous extremities of the delicate olfactory epithelium. But this is not all. The mind is not, so to speak, upon the other side of the epithelium. On the contrary, the inner ends of the olfactory cells' are connected with nerve fibres, and these nerve fibres, passing into the cavity of the skull, at length end in a part of the brain, the olfactor}' sensorium. It is certain that the integrity of each, and the physical inter-connection of all these three structures, the epithelium of the sensory organ, the nerve fibres, and the sensorium, are essential conditions of ordinary sensation. That is to say, the air in the olfactory chambers may be