280 VII. EARTHS AND ALKALIES.- 



sulph. acid, 6*75 alumine, 6 potash, and 28125 water: equiv. 

 60875. 



Ammonia alum, Sulphate of almnme and ammonia, Alun 

 ammoniacal. From the same minerals as potash alum, but 

 crystallized by means of urine or sulphate of ammonia. In small 

 scaly crystals, rather less soluble in water than potash alum ; lose 

 their ammonia in time. Used in dyeing certain colours. Com- 

 posed of 9.'k) sulph. acid, 6*75 alumine, 2-125 ammonia, and 

 28-125 water; equiv. 57. 



Burnt alum, Alumen ustum, A, exsiccatum, Sulphas alumince 

 exsiccatum. By melting common alum, and keeping it on the 

 fire until it cease to boil : used in colic, 3j for a dose ; externally 

 escharotic: 5lb. yield 31b. 



salts of barytes. 



Muriate of barytes, Chloride of barium, Hydrochlorate of 

 barytes, Murias barytcc. Dissolve carbonate of barytes, or rat's 

 stone, lib., in spirit of salt lib., previously mixed with water 

 31b. ; filter and crystallize by repeated evaporation. 



2. Mix sulphate of barytes, i. e. cawk, 21b., with charcoal 

 4 oz. ; keep it red hot in a covered vessel for six hours, boil the 

 mass in water 81b., strain, and to clear the liquor add spirit of 

 salt as long as it produces any effervescence ; lastly crystallize by 

 evaporation. Vermifuge, alterant ; used gr. j, bis terve in die, 

 in cancer and scrofula. 



Solutio muriatis BAiiYTiE. MuHas barytae 3j, distilled 

 water §iij ; dissolve : deobstruent, gtt. v — viij, bis terve die, in 

 cancer and scrofula : externally escharotic, to fungous ulcers and 

 specks on the cornea. 



Acetate OF barytes. By dissolving carbonate of barytes 

 in pure acetic acid, evaporating and crystallizing. 



Nitrate of barytes. By dissolving carbonate of barytes 

 in nitric acid, evaporating and crystallizing. 



The solutions of both the acetate and nitrate of barytes are 

 used to discover sulphuric acid, and the crystals of the nitrate to 

 discover, by fusion, potash, soda, or lithium in minerals. 



SALTS OF LIME. 



Hydrosulphate of lime, with sulphur (liquid). One 

 part of sulphur, two parts of subcarbonate of lime, and nine of 

 water : these are to be added together, and boiled in an earthen 

 vessel, until completely saturated ; the liquid is then to be 

 decanted and filtered. It is of a deep brown colour ; has been 

 found useful in psora : 1 oz. and a half to be rubbed in three 

 times a day. 



