On the Purity of Drugs and Medicines, g^ 



order to dlfcover the fulphuric and muriate fait, a determinate quantity of the alkali is to 

 be faturated with acetous acid, and then divided into three different glafles. By adding to 

 the firft gradually a folution of muriate of barytes, the quantity of fulphuric acid may be 

 dlfcovered, in the fame manner as mentioned before. In the fecond glafs, having let fall a 

 few drops of nitrate of filver, the quantity of muriatic acid may be inveftlgated in a fimilar 

 manner ; and by adding gradually a little tartarcous acid to the third glafs, an acidulous tar- 

 trate of pot-afh will be feparated in the form of a white powder, 300 parts of which Con- 

 tain 107 per cent, of vegetable alkali, as 75} per cent, pure alkali, free from carbonic 

 acid. 



The beft mineral alkali, free from any heterogeneous admixture, cryftallizes in oblong 

 druneated rhomboidal cryflals, as clear as glafs. It is foluble in an equal quantity of cold 

 water, and generally contains 80 parts of alkali, 64 carbonic acid, and 256 of water. 



Water of Pure Ammonia. Ph. L. Water impregnated with Ammoniac. 



The perfeBly caiijlic fplrlt of fal ammoniac, as it is ufually called, is one of thofe articles wc 

 feldom meet with. It generally contains aconfiderable portion of carbonic acid, and is alfo' 

 not fufficiently ftrong (particularly for philpfophical purpofes). If this liquid is confiderabij 

 ftrong, a phial containing exaftly 224 grains of diftilled water muft comprife no more thau 

 about 216 grains of aqua ammonia. 



Water of Ammonia. Ph. L- Solution oj Carbonate cj Pot-afh. 



In order to judge of the relative ftrength of this article, which is nothing elfe but a 

 mere folution of carbonate of ammoniac in water ; ftrong ardent fplrit may afford 

 no mean criterion of the ftrength or proper fatu ration, as well as of the purity of this 

 fluid. If this fluid be fully faturated with carbonate of ammoniac, a quantity of ftrong 

 ardent fpirit, poured flowly down the fides of the glafs, will feparate the alkaline fait, by 

 uniting with the water, which kept it in folution, in confcquence of which an opake denfe 

 coagulum will be formed on the furface where the fluids touch each otlier; and if on fliak- 

 ing them brifkly together, the whole mixture fhould become converted into a nearly con- 

 fiftent mafs, this article is very good. Whereas, on the contrary, if weak, the efFedt will 

 be far lefs confiderable, and the coagulum will conftantly remain feparated into two diftin£l 

 parts, viz. a folid and a fluid one. 



Water of ammonia fully faturated with carbonate of ammoniac has the fpecific gravity 

 1,150. 



Prepared Ammonia. Ph. L. Carbonate of Ammoniac. 



This fait fliould be totally volatile if laid on an ignited fubftance. It is frequently of- 

 fered for fale by chemlfts in the form of a coarfe powder, which is nothing elfe than a 

 mixture of muriate of ammoniac and pot-afti; this compofition ofcourfe is not entirely vola- 

 tilifed by heat The carbonate of ammoniac imported from abroad always contain veftiges 



Fa Of 



