I JO I^iiqtitr^ into the Laws of Affinitf. 



2. I begin with mixtures in which a confiderablc force of cryftallizatlon muft determine 

 the combinations which are formed. 



Experiment A. Equal parts of nitrate of lime and fulphate of pot-afh were mixed : 

 after the reparation of the fulphate of lime which was firft formed, and of which I {hall 

 fay more in the following experiments, the liquid was evaporated, and nothing was 

 obtained by the fucceflive operations but nitrate of potafli and fulphate of lime. After 

 the laft evaporation, however, fome cryftals of fulphate of pot-afti were procured ; there 

 remained but a very fmali quantity of uncryftallizable liquid, which precipitated with the 

 carbonate of foda and with the nitrate of barites ; fo that It confided of a little fulphuric 

 acid and lime, and very probably a larger portion of nitrate of pot-a(h. 



The quantity of fulphate of lime which was depofited in the courfe of the evaporation, 

 was much more confiderablc than would have been obtained from fimple folution of this 

 fait in water ; fo that its folubility was augmented by the aftion of the other fubftances. 



Experiment B. Two parts of fulphate of pot-afh, and one of nitrate of lime, gave by a 

 firft evaporation fulphate of potafti and fulphate of lime; and by the fucceeding evapora- 

 tions, nitrate of pot-alh with the two fulphates, the proportions of which continued to 

 decreafc to the laft cryftallizatlon. There remained only fome drops of the liquid uncry- 

 flallized i they did not precipitate with the carbonate of foda, but did with the nitrate of 

 barites : hence they were probably formed of fulphate of pot-afli, and a fmall proportion of 

 nitrate of pot-afli. 



Exj>eriment C. Two parts of nitrate of lime, and one part of fulphate of pot-afh, afforded 

 during the firft evaporation a fmall quantity of fulphate of lime, and by cooling, nitrate 

 of pot-afh ; the other evaporations only produced nitrate of pot-afh. In the latter, how- 

 ever, fome cryftals of fulphate of lime were perceived at the furface of the liquid. Not- 

 withftanding the refidue, which was abundant, was feveral times fubmitted to evaporation 

 and cooling, It no longer afforded cryftals of any fait. This uncryftallizable refidue treated 

 with alcohol, formed an abundant depofition, which having been diflblved in water, fcarcely 

 afforded any precipitate with the nitrate of barites ; fo that It contained little or no ful- 

 phuric acid, and confifted of pure nitrate of pot-afh : the portion difTolved by alcohol wa» 

 nitrate of lime, with a fmall portion of nitrate of pot-afh. The uncryftallizable refidue was 

 therefore compofed of nitrate of pot-afh and nitrate of lime. 



In this experiment we fee, that the fulphate of lime was rendered much lefs foluble than 

 in the preceding experiments ; but that a conCderable quantity of nitrate of pot-afh loft 

 the property of cryftallizing by the aftion exerted on It by the nitrate of lime. 



3. In thefe three experiments fulphate of lime muft have been formed, becaufe the lime 

 and fulphuric acid coming in contaft, would feparate on acccount of the infolubllity which 

 belongs to their comblnatioru 



The fulphate of lime In the experiment A and in the experiment B, was rendered much 

 more foluble than It naturally Is, by the aftlon of the fubftances which were in folution jj^ 

 but in the experiment C, its folubility was not fenfibly increafed, probably becaufe the 



nitrate 



