Tannicum Acidum

[tannic acid.]

This agent is dissolved out of nutgalls by means of ether, the solution being afterward evaporated to dryness by exposure to an oven-heat of about 212° F.

Tannic acid is a white, or, commonly, yellowish, odorless, spongy, brilliant substance, which dissolves very readily in water. In the dry state it is not altered by exposure to the air, but the watery solution absorbs oxygen, by which it is converted into carbonic acid and gallic acid; the former escapes and the latter remains behind in solution.

Tannic acid is a powerful astringent, and is, therefore, used by alloeopathic physicians whenever astringent effects are desired to be produced. It is mainly employed to arrest haemorrhages and to diminish the secretions from suppurating surfaces. It is used in the old school as a local astringent in gleet; it has been used in albu- minuria to diminish the secretion of albumen; in leucorrhcea when depending upon a simple irritation of the vaginal mucous mem- brane ; in atonic menorrhagia, etc.

We have no experience of the therapeutic virtues of tannic acid as an homoeopathic agent. Cararra states in the London Medical Gazette that two and a half grains taken three days successively produced constipation. It is very probable, therefore, that in constipation tannic acid may be serviceable, more particularly in constipation resulting from abuse of cathartic drugs, or attended with acidity of the stomach.

In the present state of our knowledge of the therapeutic properties of this agent, homoeopathic physicians can only use it as a palliative in , recent cases of haemorrhage, suppuration, secretions from the urethra, vagina and other parts. In inveterate ca^es, where the discharge is a symptom of a general scrofulous dyscrasia, this agent will be found unavailable as a curative asrent.

I would recall to your minds the fact that an infusion of galls is resorted to as an antidote in cases of poisoning by ipecacuahna and nux vomica, with whose alkaloids it forms an insoluble tannate.