146 MATERIA MEDICA. 



the carbonic acid with which it is naturally 

 combined, it becomes a strong caustic ; and 

 when diluted is sometimes employed as a 

 wash for the mange. In this state it is term- 

 ed pure kali, and is seldom used internally. 

 ( See Alkalies.) 



PRECIPITATE, RED, or Red Nitrated 

 Quicksilver. This is extremely useful as a 

 mild caustic or detergent, and has an excel- 

 lent effect in foul ulcers. It may be used 

 either alone, being finely powdered and 

 sprinkled on the affected part, or mixed 

 with various ointments. (See Detergents.) 

 It is made from quicksilver and nitrous acid, 

 but is considerably weaker than a solution 

 of that metal in nitrous acid. It becomes, 

 however, a strong and very efficacious caus- 

 tic when dissolved in nitrous acid ; in which 

 state, by proper management, it readily | 

 cures fistula, poll evil, and canker. This 

 solution may also be mixed with unctuous 

 substances, forming with them good deter- - 

 gent ointments ; or it may be diluted with 

 water so as to form a detergent lotion of 

 considerable efficacy. 



PREPARED KALI. (See Potash.) 

 PUFFBALL. The dust of puff-ball is 



