ASTRINGENTS. 9l 



ment with tar and vaseline ; diarrhoea and dysentery, 

 the sulphate together with opium ; chorea, if recent, 

 in the dog, the sulphate ; if chronic, the iron salts are 

 preferable. A solution of the sulphate with a small 

 amount of sulphuric acid may be used to check local 

 hemorrhage, excessive perspiration, or mucous dis- 

 charge. To wounds, sores, ulcers — the white wash 

 or the sulphate in solution. The chloride as a caus- 

 tic to poisoned wounds, unhealthy granulations, foot- 

 rot in sheep; as a wound dressing, two to three per 

 cent. Epilepsy — the oxide in small doses. As a 

 prompt and efficient emetic in narcotic poisoning, the 

 sulphate dissolved in warm water. 



Alumen — Alum. 



The alums are a series of compounds of aluminum 

 with a sulphate of an alkaline metal or group (potas- 

 sium, sodium, or ammonium). The official prepara- 

 tion is the potassium-alum or potassic-aluminic 

 sulphate, and is a combination of the sulphate of 

 aluminum with the sulphate of potassium; it is 

 therefore called a double sulphate. 



Preparations. — Alumen, alum, potassium alum. 

 Occurs as large, colorless, octahedral crj^stals, some- 

 times modified by cubes, acquiring a whitish coating 

 on exposure to air, odorless, having a sweetish, astrin- 

 gent taste, and an acid reaction. Soluble in 10.5 

 parts of water, insoluble in alcohol. When gradually 

 heated it gives off twenty-four molecules of water, 

 and becomes dried alum. Dose: H., 3ij.-iv. ; D., 

 gr. x.-xx. 



