33* On ihe conjl'ituent Parts of Azof* 



the tubes, did not appear to me altogether fatisfaftory. 1 

 had, indeed, formerly adopted this explanation * ; but I fooii 

 abandoned an opinion fo contrary to every thing that we 

 Icliow of caloric. I am really forry to fee an opinion fo im- 

 probable defended by chemifts of the firft rank; but the hif- 

 tory of chemiftry affords many inftances of the like kind. 

 Before the immortal Lavoifier had profcribed phlogifton, the 

 iStahlians extricated themfelves from their embarrafftnent 

 in a manner abfolutely fimilar. They put oxyd of mercury 

 in a crucible, {hut the crucible in the clofeft manner poffi- 

 ble, and expofed it to a ftrong heat. On opening it after it 

 had cooled, the mercury was found fluid, fiut as fuch a re- 

 duftion, according to the dofitrine of Stahl, could not take 

 place without the intervention of phlogifton, the Stahlian? 

 were afked to explain thi^ phenomenon fo contrary to their 

 do6lrine. Their anfwer was, that the phlogifton had palfed 

 through the crucilale to join itfelf to the mercury. Even 

 Bergmann and Scheele were fatisfied with this abfurd ex- 

 planation f 3 which proves that the fpirit of fyftem mifleads 

 the ableft men, and renders them ridiculous in the eyes of 

 pofterity, more enlightened, and lefs (laves to prejudice. I 

 (ball {how ttiat azot does not pafs through the fides of tubes, 

 and that phlogifton does not pafs through crucibles. The 

 experiments which Prieftley made to prove that the air pafles 

 through earthen retorts, does not prove what he pretended 

 to prove. He faw the retorts fmoke oh the outfide, but the 

 water, as he imagines, did not pafs through : the exterior 

 part of the earthen retort only attradled the water of the at- 

 niofphere. 



As I propofe, in a jjarticular work on azot, to give a detail 

 of the numerous experiments I have made to afcertain it3 

 nature, I {hall confine myfelf at prefent to a general view of 

 them, as well as of the refults which I think myfelf autho- 

 rifed td deduce from thern. I think, then, that I may fafely 

 atfert, that azotic gas is obtained : 



I. When water is boiled in an earthen retort imglazed in 



* AnfiKiigfgrumie der antipblogi/lifchen cbemie, fccond edition, p. 89, 90; 

 \ Scbfele ^jQit luft unci finer i edition of Lconhardi, p. 4*. 



