The dose is from two to ten grains, to be repeated, in chronic cases, three or four times a day; in those requiring a speedy impression, every hour, two, or three hours. The medicine may be given in pill or solution. In the latter form, it is best administered in connection with syrup; which may be either simple, or medicated by the addition of some agreeable flavouring substance, as one of the aromatic volatile oils or tinctures. Syrup of orange peel or of ginger may be for the purpose. The strength of the eolation should be such, that from one to four fluidrachms may contain the required dose of the medicine.

2. Externally, tannic acid may be used for all the purposes for which astringents are indicated, and will be found among the most effective of them. It has been specially recommended in the purulent ophthalmia of infants; in epistaxis and chronic coryza; in common and pseudomembranous angina, prolapsed uvula, ulcerous affections of the mouth and fauces, excessive salivation, bleeding and spongy gums, bleeding from the socket of an extracted tooth, etc.; in gonorrhoea, gleet, leucorrhoea, and prolapsed uterus; in bleeding from the rectum, prolapsus ani, and hemorrhoidal affections generally; and finally, in flabby and fungous ulcers, and various eruptive affections. In these complaints it may be used in solution, powder, or ointment. For injection into the eye, the nostrils, the urethra or vagina, and the rectum, and for gargles, the form of solution should be used, the medium strength of which may be five grains to the fluidounce of water. A much stronger solution, containing one part of the acid to three of water, has been recommended in purulent ophthalmia, and for ulcers and specks on the cornea; while one considerably weaker, containing not more than a grain or two in the fluid-ounce, to begin with, may be used as a collyrium in commencing or retreating inflammation of the conjunctiva, of the catarrhal character. Indeed, it is asserted that from one to two drachms in the fluidounce of water may be employed in common acute ophthalmia, dropped into the eye, not only without inconvenience, but with extraordinary curative effect. (G. It. Sheraton, Med. T. and Gaz., Sept. 1863, p. 272.) A solution of the strength of a drachm to the fluidounce has been strongly recommended in chilblains. Naevi have been cured by the injection into them of a solution of the same strength. (Haynes Walton, Med. Times and Gaz., xvi. 612.) As a local application tannic acid has also been employed dissolved in glycerin, and has proved very advantageous in the hands of some practitioners. In the form of powder, it has been used in epistaxis. being snuffed up by the nostril, or blown up through a quill; and as a remedy in spongy gums, and foul old and bleeding ulcers, to which it may be applied by sprinkling or dusting it over the surface. It has been thought to be very efficacious in chronic inflammation of the lachrymal sac; being applied, by means of a fine camel's-hair pencil, to the vicinity of the puncta lachrymalia, after the matter has been evacuated from the sac by pressure.

An ointment is now officinal (Unguentum Acidi Tannici, U. S.), made by rubbing thirty grains, first with thirty minims of water into a paste, and afterwards with a troyounce of lard; and the preparation may be weakened by adding any desirable quantity of lard. In this form it may be used in piles, cutaneous eruptions, sore nipples, old ulcers, and chronic inflammation of the uterus and vagina. In the form of lozenges (Trochisci Acidi Tannici, Br.), each containing half a grain of the acid, it may be employed in cases of chronic angina and relaxation of the uvula; the lozenge being held in the mouth, and swallowed as it slowly dissolves.

Becqaerel has found great advantage, in cases of chronic disease of the uterus, from the introduction into the cavity of the organ of cylindrical sticks of tannic acid, about an inch long by two or three lines in diameter, made by rubbing four parts of the acid, and one of tragacanth, with enough crumbs of bread to give them due plasticity. (Ann. de Therap., a.d. 1860, p. 164.) Sir J. Y. Simpson, of Edinburgh, also, among other medicated pessaries, recommends one of tannic acid, made by incorporating ten grains of the acid with a sufficient quantity of cacao butter. (Ed. Med. Journ., May, 1865, p. 1042).

The British Pharmacopoeia directs suppositories of tannic acid, made by mixing the acid with lard, wax, and glycerin; each suppository weighing twenty grains, and containing two grains of tannic acid. A better excipient, however, would be the cacao butter. The remedy may be used in prolapsus ani, piles, and anal leucorrhoea.

Tannic acid in solution is one of the substances which has been recently used in the form of spray, by means of the atomizer. It has been employed in oedema of the glottis, laryngeal ulcerations and excrescences, and in chronic bronchitis. The strength of the solution for these purposes varies from one to twenty grains to the fluidounce of water. A stronger solution, containing thirty grains to the fluidounce, has been used in haemoptysis. (Da Costa, N. Y. Med. Journ., Oct. 1866, p. 35).