the Laws of Affinity. 201 



acid, but by the muriate of barytes; fo that this refiduum 

 was composed of fulphate of foda and a greater proportion 

 of nitrate or foda, which mutually prevented their crystalliza- 

 tion, as in experiment D. 



6. Experiment G. Equal parts of nitrate of potafh and ful- 

 phate of foda gave by lucceflive cryftallization?, I. Sulphate 

 of potafh, and lome fmall cryftals of nitrate of potafh ; 2. A 

 little fulphate of potafh, and a greater proportion of nitrate of 

 potafh ; 3. Small cryftals of nitrate of potafh, and much ni- 

 trate of foda: there was an uncryftallizable refidue, notwith- 

 standing the care which had been taken to obtain the utmofl 

 cryftallization : this refidue was formed of nitrates and ful- 

 phates; for it precipitated abundantly with the nitrate of 

 tarytes, and, after drying, it flowed on ignited charcoal. 

 This experiment ought to be compared with experiment F. 



H. One part of nitrate of potafh, and two of fulphate of 

 foda, gave, 1. Sulphate of potafh ; 2. Sulphate of potafh, and 

 fome needles of nitrate of potafh ; 3. Sulphate of potafh in 

 fmall prifnis, fufpended from a pellicle formed bv nitrate of 

 foda, fine cryftals of nitrate of potafh and nitrate of foda : 

 the refidue contained nitrates and fulphates. 



In thefe two experiments, the leaft foluble fait of thofe 

 which were formed, viz. the fulphate of potafli, w r as the firft. 

 which was cryftallized. When the proportions had been 

 thus changed, the action of the nitric acid on the potafh re- 

 fumed its fuperiority, and nitrate of potafh was formed, 

 though the liquid ftill contained fulphuric acid. 



In the fecond, the more abundant fulphuric acid gave rife 

 to a greater quantity of fulphate of potafli ; but, after the firft: 

 cryftallization, more nitrate of potafli was formed, though 

 there would have been a fufficient quantity of fulphuric acid 

 to caufe a complete change of bafe, if this exchange could 

 have been made as has been imagined . The refidue was 

 formed, even in experiment G, of fulphate of foda and ni- 

 trate of foda; and probably of a fmall quantity of fait with 

 bafe of potafh. 



7. Experiment I. Equal weights of nitrate of potafh and 

 muriate of lime were mixed together : by evaporation there 

 were, 1. Nitrate of potafh ; 2. Muriate of potafh, in which 

 was found a little nitrate of potafli : the refidue gave with the 

 fulphuric acid an abundant precipitate of fulphate of lime, 

 and vapours of muriatic and nitric acid were difengaged. 



K. The experiment having been made with two parts of 

 muriate of lime, and one of nitrate of potafh, an abundant 

 cryftallization of muriate of potafli was produced, with no 



appearance 



