The functions of the tongue are gustation, prehension (in man and monkeys this function is supplied by the hand), mastication, insalivation, deglutition, and speech; to which may be added spitting and whistling, and in the case of the gasteropoda, triturition of the food.
Among the diseases of the tongue may be mentioned INFLAMMATION or GLOSSITIS The most marked characteristics of this affection are great swelling, tenderness, and difficulty in speaking and swallowing. It rarely occurs as an idiopathic or spontaneous affection, but often accompanies severe salivation. It must be treated by purgativesand low diet, and by gargling as in ordinary salivation (q.v.). Incisions are sometimes useful, both to relieve tension, and by the depletion that ensues. Cases occasionally occur in . which the tongue suddenly enlarges to an immense size, so as almost to cause suffoca tion, without any true sign of inflammation.—See Druitt's Surgeon's Trade-mecum, 8th ed., p. 454, foot-note.
Hypertrophy, or persistent enlargement of the tongue, sometimes results from an imper- ' fectly cured case of inflammation; but is probably in most cases congenital, although perhaps not noticed for a year or two. Bertholin (Hist. Centur., iii. p. 85) mentions the ease of a male child horn with the tongue protruding out of the mouth as large as a nibert; and as the child grew, the tongue increased to the size of a calf's heart. For a. reference to various cases, and for the mode of treatment, we may refer to a memoir by Dr. Humphry in vol. 36 of the 111edico-Chir. Transactions. One of the most common forms of disease of the tongue is ulceration, which may arise (1) from the irritation of a decayed tooth with a sharp jagged edge; or (2) from constitutional syphilis; or (3) from a disordered condition of the digestive organs. In the first case the tooth must be removed; in the second, iodide of potassium with sarsaparilla should be tried; and in the third, the complaint generally yields to regulation of the diet and of the digestive organs, and sedatives at bed-time. M. Lawrance recommends a mixture of compound decoction of sarsaparilla with compound decoction of aloes, three times a day, and four grains of extract of hyoscyamus at bed-time, with advantage. Cancer of the tongue
occurs either in the hard or in the epithelial variety. There is a popular belief that this terrible disease may be excited by the irritation caused by a broken tooth, or by smoking a clay pipe; but on comparing the prodigious numbers of jagged teeth and of clay pipes with the rare cases of cancer of the tongue, we must at once reject this hypothesis. All that such sources of irritation can effect is to determine the exact seat of development of cancer in persons predisposed to it. A. typical case of epithelial cancer of the tongue occurred in the person of prof. Reid of St. Andrews, the eminent physiologist. In Dec., 1847, his age being then 39, and his health good, he noticed a small ulcer on the right side of his tongue; it slowly extended, and acquired hard everted edges, but caused little incon venienco. In July, 1848, it had attained the size of a five-shilling piece; its surface and edges were ragged, and it caused considerable pain, especially at night. A hard ridge could be felt all round the ulcer, and the glands beneath the jaw became enlarged. The health by the end of August had completely given way from the pain, when the diseased part of the tongue was removed by the late sir William Fergusson. In less than a month the wound had healed, and the health was re-established. In November the enlarged glands were removed, but the disease returned in their scars, and spread till it caused death in July, 1849. The only treatment which can be adopted with any chance . of success is full and early, extirpation. Prof. Syme succeeded in removing the whole organ, without even—strange to say—much affecting the patient's speech or power of deglutition. longue-tie is an affection for which infants are often brought to the sur geon, and which is often operated on when this might be dispensed with. The division of the frcenum with a blunt-pointed pair of scissors, with their point directed downward, is very easily performed, and fortunately does no harm to the child. Children who do not speak so soon or so clearly as is expected by their mothers, are always supposed to have tongue-tie.