[14] M. Cadet de Gassicourt recommends the following compound as a safe and excellent dentrifrice, viz. of white sugar and powdered charcoal each one ounce, of Peruvian bark half an ounce, of cream of tartar one drachm and a half, and of canella twenty-four grains, well rubbed together into an impalpable powder. He describes it as strengthening to the gums and cleansing to the teeth, and as destroying the disagreeable odour in the breath which so often arises from decaying teeth; and as a _preventive_ of toothach, I have heard washing the mouth and teeth twice a-day with salt and water strongly recommended by a gentleman who had both experienced and observed much benefit from it. [15] Experiments and Observations on the Gastric Juice and the Physiology of Digestion, by William Beaumont, M.D. Platsburgh, 1833, p. 67. [16] See Roget’s Bridgewater Treatise, note at p. 58, vol. ii. [17] Id. vol. ii. p. 59. [18] For a full explanation of the nature, importance, and laws of respiration, see the author’s Principles of Physiology, &c. 4th edition, chap. vii. [19] Cuvier’s Règne Animal, vol. ii. p. 295. [20] The above descriptions and figure are taken, with slight alterations, from the Treatise on Animal Physiology in the Library of Useful Knowledge. [21] Principles of Physiology, 4th edition, &c. pp. 142, 192, and 277. [22] From πνευμων, _pneumon_, a lung, and γαστηρ, _gaster_, the stomach, or _lung and stomach_ nerve. [23] Philosophy of Health, vol. i. p. 80. [24] Cyclop. Pract. Med. vol. ii. p. 635.