Neutral Salts. 285 



distilling nitre with oil of vitriol in water, evaporate, crystallize, 

 and dry the crystals: a cooling purgative, 3j to 5ij. 



Sulphas potass.e cum sulphure. Mix nitre and flowers 

 of sulphur ana p. aeq. ; throw them by small portions into a red 

 hot crucible, and let the mass cool. Aperient, deobstruent, and 

 depurative ; in cutaneous afl'ections and obstructions of the viscera. 

 In its medical effects it agrees with sulphureous mineral waters, 

 Nvhich contain a proportion of neutral salt. A saline solution 

 analogous in operation to that of the Harrowgate waters may be 

 made, by dissolving two drachms of this salt, one drachm of cream 

 of tartar, and one ounce and a half of sulphate of magnesia, in 

 two pounds of water. Dose jij to 5iv. 



Sal polychrestus Glaseri, Proceed as before ; but as soon as 

 the deflagration is over, raise the heat, keep the mass in fusion for 

 some time, pour it out, dissolve it in water ; filter, evaporate, and 

 crystallize. 



Red argol, Tartarum rubnim. From red wines. 



"White argol, Tartarum album, Supertartris potasscB impurus. 

 From white wines; the essential salt of the grape deposited 

 during the fermentation of the wine, especially in the northern 

 wine countries, where the fruit does not ripen tnoroughly. Used 

 IS fluxes, for preparing the best subcarbonate of potash, in dyeing, 

 md many arts. 



Crystals of tartar, Crystalli tartaric Potasses supertartras. 

 Obtained by boiling white argol in water, with some white clay ; 

 filtering, evaporating, and crystallizing. 



2. By clarifying the solution with white of eggs and woodashes, 

 instead of white^clays, as in the former: from Venice and Mont- 

 pell ier. 



Cream of tartar, Cremor tartari. Formerly the skin of 

 crystals that formed on the surface of the ley during evaporation ; 

 now used for the crystals reduced to powder : cooling, laxative, 

 may be taken ad libitum ; used as a diuretic in dropsy. 



Soluble tartak, Tartarum soluhilc, T. tartarhatum^ Kali 

 tnrtarisatum^ Tnrtris potassoi^ PotasscB tartras, Tartar as kali. Dis- 

 solve pearlash lib. in a gallon of water, add cream of tartar as long 

 ns any efTervcscence arises, z. <?., rather less than Olb. ; evaporate 

 ind crystallize : purgative .^j ; laxative 3j to iij ; also added to 

 nna and resinous purgatives 3j to 3J, to prevent their griping. 



British cream of tartar. Argol 3 cwt., sal enixum 1 

 cwt. ; dissolve in water and crystallize : sold for cream of tartar. 



Soluble cream of tartak, Tartarum boraxatum^ Tartris 



