270 



ANALYSIS OF BRITISH AND FOREIGN SALT. 



Separation 

 and calcula- 

 tion of the 

 Mfthy sul* 



p hates.. 



of lime and muriate of magnesia. Thus, if 20 grains of a 

 mixture of the two muriates yielded 15*1 of ammoniaco- 

 magnesian phosphate, it is obvious, that the mixture 

 must have consisted of equal weights of muriate of lime 

 and muriate of magnesia. 



(B. d.) The estimation of the proportion of mjuriate of 

 lime, in a mixture of this salt with muriate of magnesia, 

 was sometimes performed in a different way. Toacold solu- 

 tion of a known weight of the two salts, superoxalate of pot* 

 ash was added ; and the precipitate was collected, washed, 

 and dried at about H5u e Fahrenheit. Of this precipitate I 

 had previously found, that 116 grains are formed by the 

 decomposition of 100 grains of dry muriate of lime. From 

 the quantity of oxalate of lime it was easy, therefore, to in- 

 fer that of the muriate, from the decomposition of which it 

 resulted; and this, subtracted from the weight of the two 

 salts, gave the weight of the muriate of magnesia. 



II. To separate and estimate the earthy Sulphates. 



(C.) The portion of salt, which had resisted the action of 

 alcohol, was dissolved by long boiling in sixteen ounce mea- 

 sures of distilled water, and the solution was filtered. On 

 the filtre a small quantity of .undissolved matter generally 

 remained, which was washed with hot water, till it 

 ceased to have any action. The weight of the insoluble 

 portion was then ascertained. 



(C, a.) By this operation were dissolved, not only the mu- 

 riate of soda, but all the other salts, insoluble in alcohol, 

 which might be mingled with it. To the solution carbo- 

 nate of soda was added ; and the liquid, which in most ca- 

 ses gave, on this addition, an abundant precipitate, was 

 boiled briskly for several minutes, in order that none of the 

 earthy carbonates, which were separated, might remain dis- 

 solved by an excess of carbonic acid. 



(C. b.) The precipitated earths were allowed to subside, 

 and were wett edulcorated with boiling water, the washings 

 being added to the liquor first decanted from the precipitate. 

 To the-,e minted liquids (after the addition of more muriatic 

 acid thar was requi/ed for saturation) muriate of barytes 

 was added, till it ceased to occasion any further precipitate. 



The 



