420 ■ VEGETABLE DRUGS 



dular (mucous) ducts with coagulated secretion, and by constriction of 

 the surrounding parts. It lessens the flow of mucus and of the digestive 

 juices in the stomach and intestines by the same process. In the stomach 

 tannic acid precipitates protein but as digestion proceeds and peptones 

 are formed, with which tannic acid does not combine, the acid is set free 

 again and acts as an astringent. Large doses irritate the alimentary 

 canal and may create vomiting and diarrhea. Tannic acid in the bowels 

 is converted first into sodium tannate, and then sodium gallate, which is 

 not astringent. For this reason tannic acid only acts a short time in the 

 intestine and other drugs are more often used in diarrhea. Traces appear 

 in the blood and urine as sodium tannate or gallate. Of the tannic acid 

 swallowed not more than 1 per cent, is excreted in the feces and urine 

 as tannic or gallic acid. All the rest is oxidized in the body. Gallic 

 acid does not coagulate albumin or gelatin and has a very feeble astringent 

 action — like that of any weak acid — so that tannic acid should always be 

 used for a local effect. The remote astringeijt influence of tannic or 

 gallic acid on the tissues, after absorption in the form of sodium gallate 

 or tannate, is nil. Catechu and kino are often chosen in place of tannic 

 acid in the treatment of diarrhea, because they are less soluble (than 

 tannic acid), and their colloid and extractive matters prevent the con- 

 version of tannic acid into non-astringent salts, and the contained cate- 

 chutannic acid comes in contact with the intestinal mucous membrane for 

 a longer time. The salts of tannic acid (tannates) are not asti'ingent. 



Uses External. — Tannic acid is a valuable astringent in a great 

 variety of local inflammatory lesions. In the form of the glycerite, tannic 

 acid may be applied advantageously to the skin in moist eczema, and as 

 a remedy for frost bites. It is a useful application for sore and cracked 

 teats. The mouth is painted with glycerite for the cure of ulcerative or 

 aphthous stomatitis. The same preparation is injected into the ear in 

 otorrhea of dogs, and into the vagina to arrest vaginitis and leukorrhea. 

 Pure tannic acid is an excellent agent when dusted upon raw surfaces, 

 ulcers, and sores ; and to stop bleeding in slight wounds. An aqueous 

 solution is useful in leukorrhea (2-5 per cent.), in eczema (5-10 per 

 cent.), as a high enema in dysentery (1 per cent.), and to kill ascarides 

 (1-2 per cent.) in the rectum. A one per cent, aqueous solution is some- 

 times utilized as an inhalation in subacute laryngitis, tracheitis, and 

 bronchitis. Powdered opium and nutgall ointment (1-14), or glycerite of 

 tannin, are serviceable in hemorrhoids and rectal fissures, ulcers, or pro- 

 lapse of the rectum. 



Uses Internal. — Tannic acid is exhibited in powder or solution to 

 arrest bleeding in the stomach. It is an astringent in diarrhea and an 

 hemostatic in intestinal hemorrhage, given in ball or pill, and often with 

 opium. Tannic acid is an antidote to alkaloids, metallic salts, and tartar 

 emetic, forming comparatively insoluble tannates, which should be 

 removed if possible by evacuation of the stomach. 



Tannalbin is a tasteless, odorless, non-irritating, brown powder of tannic acid 

 (50 per cent.), combined with albumin by heat, and only soluble in the pan- 

 creatiS juice in the bowel. It is more suitable for young animals in diarrhea 

 than is tannic acid. 



Dose. — H. & C, 3i-iv, (4-15); foals & calves, gr.xx-xl, (1.3-2.6); D. & C. 



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