ROCHELLE SALTS. 89 



and saline ; sometimes contains sulphate of soda as an impurity. 

 One of the best saline cathartics, and very extensively employed. 

 Dose for an adult 3j ; best given in carbonic acid water. 



Glauber's Salts. — (800^3 Sulphas, U. S.) 



Procured as the residuum after making muriatic acid; also from 

 the bittern of sea-water. Occurs in four-sided crystals ; efflorescent ; 

 contain more than 50 per cent, water of crystallization ; more solu- 

 ble at 90° than 212° ; taste, very nauseous and bitter ; not so much 

 used as Epsom salts ; — dose about the same. 



Sulphate of Potash. — (Potass^ Sulphas, U. S.) 



Formerly called vilriolated tartar ; the residuum after the manu- 

 facture of nitric acid, from sulphuric acid on nitre ; contains no water 

 of crystallization ; occurs in small white and very hard prismatic 

 crystals ; not very soluble ; not much used as a cathartic, but chiefly 

 in the preparation of Dover's powder. Dose, 3ss. 



Tartrate of Potassa. — (Potass^ Tartras, U. S.) 



Formerly called soluble tartar. Prepared by adding cream of 

 tartar to a hot solution of carbonate of potassa. The crystals con- 

 tain no water of crystallization ; they are deliquescent, have a cool- 

 ing bitterish taste, and are very soluble in water ; — not much used at 

 present. Dose, |ss. to 3j. 



Cream of Tartar. — (Potass^ Bitartras, U. S.) 



Exists in the juice of grapes, from which it is deposited during the 

 vinous fermentation, because it is insoluble in alcohol. It encrusts 

 the sides of the wine casks, and is detached in the form of thick 

 cakes of a reddish-gray colour, and sold under the name of argot. 

 This, when properly purified, assumes the form of white transparent 

 crystals of pure cream of tartar. It is generally kept powdered. 

 Taste acid ; soluble in sixty parts of cold water, and in fifteen of 

 boiling water. 



Effects. — A hydragogue cathartic ; also diuretic and refrigerant. 

 Very useful in dropsy ; much employed, in combination with jalap, 

 in chronic afiections of the joints ; and with sulphur in haemorrhoids. 

 Best given in sweetened water, or as an electuary with molasses ; — 

 dose, 3ss. to 3j. 



Rochelle Salts. — (Sod^ et Potass^ Tartras, U. S.) 



Made by adding carbonate of soda to cream of tartar. Occurs in 

 large white transparent prismatic crystals of unequal sides ; efflores- 

 cent ; very soluble in water ; taste less unpleasant than most of the 

 others. It is one of the best of the saline cathartics. Dose 3j to 3iss. 



The Seidlitz powders consist of a mixture of 3ij Rochelle salts, 



8* 



