568 VEGETABLE DRUGS 



Properties. — White, or pale fawn-colored, silky, inter- 

 laced needles or triclinic prisms; odorless; having an 

 astringent or slightly acidulous taste ; permanent in the air. 

 Soluble in ] 00 parts of water, and in 5 parts of alcohol ;. in 

 40 parts of ether, and in 12 parts of glycerin. Very slightly 

 soluble in chloroform, benzol, or benzin. 



IncompatiUes. — Metallic salts and spirit of nitrous ether. 



Dose.—R. & C, 3ii.-5ss. (8.-15.); Sh. & Sw., 3 ss.-i.. 

 (2.-4.); D., gr.v.-xx. (.3-1.3). 



PREPARATIONS- 



Unguentuvi Oallce (1-4). (U. S. & B. P.) 

 Unguentum Oallce Cum Opio. (B. P.) 



Action and Uses. — Since tannic acid is absorbed as gallic 

 acid, and since the latter drug is less irritating, it follows 

 that gallic acid is preferable when it is proposed to exert an 

 astringent effect through the circulation. Gallic acid is a 

 feeble local astringent, and therefore tannic acid is always a 

 better agent for topical use. The remote astringent action 

 of gallic acid is questionable, but successful results are 

 alleged to have followed its administration in the treatment 

 of haemorrhage from the lungs, uterus and kidneys, and in 

 polyuria, albuminuria, bronchorrhcea, leucorrhoea, and 

 excessive sweating. 



Ergot has been generally considered superior to gallic 

 acid for the purpose of producing general constriction of the 

 smaller vessels, and arrest of internal haemorrhage. 



Pyrogallol. Pyrogallol. CeH, (OH),. (U. S. P.) 



Synonym. — Pyrogallic acid. 



Derivation. — A triatomic phenol obtained chiefly by the 

 dry distillation of gallic acid, HCHsO^ = G,^, (OH), -f CO^. 



Properties. — Light, white, shining laminae, or fine needles; 

 odorless, and having a bitter taste ; acquiring a gray or 

 darker tint on exposure to the air and light. Soluble in 1.7 

 parts of water, and in 1 part of alcohol ; also soluble in 1.2 

 parts of ether. 



