MEDICINAL USES 647 



and dysentery the slowly dissolving catechus and kino are 

 sometimes preferred to tannic acid, as they reach the 

 intestines and exert their in-contact effects before they are 

 neutralised. They are frequently prescribed with chalk, 

 acids, aromatics, and opium, and given either in bolus or 

 mucilage. For arrest of internal haemorrhage, neither 

 tannic nor gallic acid is so effectual as ergot, ferric-chloride, 

 or lead acetate and opium. Stockman's investigations 

 show that gallic acid, even in full doses, has no special 

 general astringent action. Both tannic and gallic acids 

 are used as antidotes in poisoning by alkaloids ; but in 

 combating metallic poisoning they are not so serviceable 

 as other chemical antidotes, and as demulcents. 



Externally, tannic acid is used with glycerin and water in 

 the weeping stages of eczema ; as an astringent wash with 

 opium in prolapsus of the uterus or rectum ; while it also 

 checks the discharge and allays the irritability of otorrhcea, 

 which is common in dogs. Tannic acid and antipyrine, ten 

 parts of each, with 100 of alcohol, form an excellent applica- 

 tion for soft, ulcerating, bleeding surfaces. For piles in dogs, 

 tannic acid is used in substance, or as an ointment, opium 

 being added if there is much irritability ; and such applica- 

 tions are often advantageously alternated with calomel 

 ointment. Tannic acid mixed with boric ointment and 

 sometimes with opium is useful for burns. For nasal 

 catarrh it may be used mixed with starch, or iodoform, as 

 an insufflation. 



DOSES, etc. Of tannic acid horses take grs. Ixxx. to 3ij- J 

 cattle, 3i y - > sheep and large pigs, grs. xxx. to 39 ; dogs 

 and cats, grs. ij. to grs. x. Powdered galls are used in about 

 double these doses. Glycerin of tannic acid, made by 

 stirring one part of acid with five of glycerin, is a soothing 

 antiseptic astringent, used diluted with water as required. 

 Gall and Opium ointment is made with 37 grains powdered 

 galls, 15 grains opium, and 148 grains of benzoated lard, 

 or with vaseline. A styptic colloid may be prepared with 

 one of tannin and eight of alcohol, mixed with four of 

 collodion. 



Pyrogallie acid is an astringent, and caustic, recom- 

 mended in cases of psoriasis and ringworm, and for 



