Experimental physiology.

  • Edward Albert Sharpey-Schäfer
Date:
1912
Catalogue details

Licence: In copyright

Credit: Experimental physiology. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    TASTE AND SMELL Taste.—(a) To test the localisation of taste, direct the subject to close his eyes and put out his tongue. This organ is then dried, and different parts are touched with a small brush or a glass rod moistened with the sapid substance in solution. After each observation the mouth must be rinsed with water. The following solutions may be used for testing the four qualities of taste, viz. : for Utter, 1 per cent, solution of quinine sulphate ; for sweet, 5 per cent, solution of sugar; Ayr I < I I : I I I I I 1 I I t I I I I I t ] I I M • FIG. 8.3.—ZWAARDEMAKER'S OLFACTOMETER. 71, NOSE PIECE ; SCT, SCREEN; t, POROUS TUBE Sliding over Graduated Glass Tube. for acid, 2 per cent, solution of citric acid ; and for salt, 5 per cent, solution of common salt. Notice the time which intervenes between the application of the sapid substance and its effect. Record your results as regards localisation upon an outhne plan of the tongue. {h) Chew a leaf of Gymnema sylvestris, or paint with cocaine solution, and determine whether the taste of any of the varieties of sapid substances is affected. (c) Test different parts of the tongue by applying closely-set electrodes arranged to conduct a weak faradising current. Smell.—The sense of smell is tested by Zwaardemaker's olfactometer, which conBists of a glass tube with one end adapted to the nostril, while over the other end a tube constructed of, or impregnated with, the odoriferous substance, slides; so that a greater or less amount of its inner surface can be exposed to the air which is passing through the glass tube into the nostril (fig. 83). Ill
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