[ XXX ] 



" have reprefented the naked facts 

 " as I obferved them ; and, having 

 u no great attachment to any par- 

 " ticular bypotbejis^ I am very will- 

 " ing that my reader fliould draw 

 " his own concluiions for himfelf." 

 Dr. Priefdey, having obferved that 

 bubbles of air feemed to hTue fpon- 

 taneoufly from the (talks and roots 

 of fever al plants kept in the water, 

 fufpected immediately, that perhaps 

 this air, if found better than com- 

 mon air, had been percolated through 

 the plant, and purified by leaving 

 its phlogifton in the plant as its 

 nourifhment. With this view he 

 plunged many phials containing 

 fprigs of mint in water, laying 

 them in fuch a manner, as that 

 any air, which might be difcharged 

 from the roots, would be retained 

 in the phials, the bottoms being 



a little 



