^m Neutbal Salts. 279 



^na a rubefacient, or vesicant. — Principal officinal preparation, 

 Ammoniae hydrosulphuratum, D. E. ; Linimentum ammoniae, 

 D. L.\ Liniment, camph. comp., D, L,\ Liniment, hydrar- 

 gyria L, 



Henrys pure ammonia-icater. Made up to the sp. gr. of '970 ; 

 one measure is equal in saturating acids to one measure of hiij 

 carbonate of potash-water. Used in testing liquors. 



Liquor volatilis cornu cervi cum calce. Spirit of 

 hartshorn 41b., fresh slaked Hme lib., distil into water kept cool, 

 and, if necessary, adjust its specific gravity by the addition of dis- 

 tilled water, or by repeating the distillation ; antacid, stimulant. 



NEUTRAL SALTS. 



Water, when saturated with any one salt, will dissolve another 

 or even several other salts; hence a small quantity of water, 

 poured upon a large mass of impure salt, saturates itself with 

 the most abundant, and then, dissolving the other salts which 

 render it impure, leaves the remainder in a state of purity. 



!" SALTS OF ALUMINE. 



Alum, Lump alum, Sulphate of alumine and potash^ Rock alum, 

 Alun de roche, Alun de glace, Alumen vulgare, Sulphas alumince. 

 In large lumps, formed by pouring a solution at 50 deg. Baume 

 into barrels, where it forms a nearly solid mass. Obtained from 

 different minerals by elixation and crystallization, previously 

 adding potash or potash and urine: tonic, astringent, gr. v. — xx; 

 in gargles, 3ss to water 3iv ; in eye- waters and injections, gr. xij 

 to water 5vj : used largely by the dyers, also to harden tallow for 

 mould candles, and many other purposes in the arts. 



Roach alum, Alun Jin, Alumen crystallinum, A. rupeum. 

 Crystallized from a solution at ^Zo or 30 deg. Baume. In pyra- 

 midal lumps of crystals ; preferred by the dyers in certain pro- 

 cesses. 



Alun de liege. Impure, but by solution and recrystallizcu 

 tion is rendered very pure. 



Italian roach alum, Alun de Rome, Alumen Romanum, A, 

 rultrum. In crystals, pale red when broken, and covered with a 

 reddish efflorescence: not refined; used by the dyers; contains 

 no ammonia nor iron. 



Turkey alum, Alun de Smyme, Alumen de Rochi, From 

 the orif^inal manufactory of Rcx:cha, in Syria ; in pieces the size 

 of an almond to that of an egg, covered with a reddi.sh efflores- 

 cence. — The potash sulphates of alumine are composed of ^ 



