An elementary treatise on human physiology : on the basis of the Précis élémentaire de physiologie / par F. Magendie.

  • Magendie, François, 1783-1855.
Date:
1844
Catalogue details

Licence: Public Domain Mark

Credit: An elementary treatise on human physiology : on the basis of the Précis élémentaire de physiologie / par F. Magendie. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    able. We speak, however, of a musklike odour, aromatic, and fetid odours, &c. They are likewise sometimes distinguished into fugitive and tenacious. For the most part, however, we can only designate them by comparing them with that of some known body. Nutritious, medicinal, and even poisonous qualities have been attributed to odours; but, in such cases, these opinions seem to have been formed by confounding the influence of odours with the effects of absorption. A man who pounds jalap for some time will be purged, as if he had taken its substance into his stomach. This effect cannot be properly referred to the effect of odour, but to the fine particles of the jalap which are floating in the air, and which are thus introduced into the circulation, either with the sal- iva, or the air which he respires. It is to the same cause to which we must attribute the intoxication of persons exposed for some time to the fumes of spirituous liquors. The air is the ve- hicle by which odours are generally transported to a distance, but they are also produced in a vacuum. There are some bodies which dart forth their odoriferous particles with a considerable degree of force; but this subject has not received the attention which it deserves. It has not been fully ascertained if odours ob- serve, in their progress, anything analogous to the convergence and divergence, reflection and refraction of luminous rays. Odours attach themselves to, or combine with, many fluids, as well as many solid bodies; a method which is often taken to preserve them for a long time. Liquids, vapours, gases, and many solid bodies, when reduced to an impalpable, or even coarse powder, have likewise the property of acting upon the organs of smell. Apparatus of Smell. The olfactory apparatus may be compared to a sort of sieve, placed in a spot over which the current of air that is introduced into the chest in respiration passes, and which is destined to de- tain all the foreign bodies which may happen to be mixed with the air, particularly odours. This apparatus is extremely simple. It differs essentially from that of vision or hearing in this, that we do not find before the nerve any parts which are placed there to modify the physical effects of the excitant, the nerve being, in a great measure, naked. The apparatus is composed of the pituitary membrane which covers the nasal cavities, of the membrane which lines the sinuses, and of the olfactory nerve and different filaments of the nerve of the fifth pair. [The following is a vertical and longitudinal section of the hu- man nostril. The olfactory nerve is seen passing thfough the cribriform plate of the ethmoid bone at O, to be distributed to the pituitary membrane which covers the nasal passages and cells. Several of these cells are seen, as the sphenoidal sinus S, the frontal sinus F, and one of the ethmoidal cells C. N is the nasal bone; P the