&t Lembigton Priors: 353 



The triple compound of which I have treated, is mixed 

 with the deliquefcent fait of magnefia, but uot wholly; for 

 it may be difcovered with the non-dcliquefcent falts, though 

 thefe have been feparated carefully by fpirit of wme. The 

 tartrite of potaili indicates it in both. Oxalic acid does the 

 fame thing, feparating a white powder with fome cryftalline 

 "grains which are the oxalat of manganefe. (See Bergman; 

 Diflert. viii. 24.) 



XIV. THE RESIDUUM OF DIFFICULT SOLUTION. 



After thefe falts had been feparated there remained a large 

 refiduum, which was not foluble except in a great quantity 

 of water. This has a cryftalline form like fulphat of lime; and 

 the ulual reagents ihewed it, in fact, to contain both lime and 

 fulphuric acid. But the weight of this refiduum, from a 

 gallon of water, was no lefs than 112 grains : a larger quan- 

 tity than could be diffolved in a gallon of water, if it were 

 pure fulphat of lime. If it be cOnfidered that the water re- 

 quires fomc evaporation before thefe cryftals begin to fepa- 

 ratc, the proportion is {till more increafed. There muft be y 

 therefore, fomething peculiar in the compofition of the fait, 

 or in the foluble powers of the water. Other experiments 

 (hew the fame thing. 1. Sulphuric acid dropped into the 

 water precipitates copioufly fulphat of lime. This cannot 

 be effected by the decompofition of the muriat of lime ; 

 fince we have already feen that no fuch fait is to be 

 found (xili.). Indeed it cannot exift in the fame folution 

 with fulphat of foda, as thefe falls decompofe each other*. 

 2. Sometimes a more unexpected appearance than this 



' It is afton! tiling that this fritt fhoald have bt«n neglected, and that in 

 recent paV>!!c 't : .or;s. Mr. Schmeififer, in his r.nalyfis of the waters ofKil- 

 bum Wells (Phil. Tranfac), has joined together fulphat of foda, fulphat 

 of magnefia, and muriat of lime, a^ being contained in thefe waters. Dr. 

 Gimeu has alio put into tliecoii pofition of the fulphurwell arHarrowg=ire 

 fulphat of magnefia and muriat of lime ; an error the more unaccountable, 

 as Bergman has cxpreffly remarked this decompofition in his DhTertatton 

 •nthe Analyfisof Water;. See Diflert. ii. 7. M« 



Vol. 1, A a toJse* 



