158 INORGANIC AGENTS 



and tasteless ; permanent in dry air ; insoluble in water or 

 alcohol. 



Dose. — Same as alum. 



Alumini Sulphas. Aluminum Sulphate. Al2(SOj8 4-16H20. 



(U.' S. P.) 



5'?/7i07i2/m.— Sulphate of aluminum, E.; sulphate d'alum- 

 ine, Fr.; schwefelsaure thonerde, G. 



Derivation. — Aluminum hydroxide [Al (0H)3] is dis- 

 solved in diluted sulphuric acid/ and the solution is filtered 

 and evaporated to dryness. 



Properties. — A white, crystalline powder, without odor, 

 having a sweetish and afterwards astringent taste ; perma- 

 nent in the air ; soluble in 1.2 parts of water ; insoluble in 

 alcohol ; reaction acid. 



Dose. — Same as alum. 



Aluminum Salts. 



Action External. — Dried alum is a superficial caustic, in 

 contact with raw surfaces, on account of its affinity for 

 water. It is only used externally. Alum has no action on 

 unbroken skin, but applied to mucous membranes or 

 denuded parts it is antiseptic and astringent; coagulates 

 albumin of discharges; combines with albumin of the 

 tissues, which it coagulates ; squeezes blood out of the 

 vessels ; reduces inflammation and makes the part whiter, 

 tougher and denser. Alum is an haemostatic, stopping 

 bleeding by compression of the structures surrounding the 

 vessels, and by causing blood to clot. Alum coagulates 

 casein and gelatin in the presence of an alkali. 



Action Internal. — Stomach and Intestines. — Enormous 

 doses of alum produce gastro-enteritis, while large doses 

 cause vomiting in carnivora. All the secretions are dimin- 

 ished in the alimentary canal, and constipation ensues, 

 unless the dose is excessive. Traces of alum are said to 

 appear in the urine, but since the salt coagulates albumin, 

 absorption cannot occur to any extent. Alum does not, 



