156 THE HISTORY OF CHEMISTRY, 



minute attention, and called it Gas, or Gas fy^ 

 vejlre. In his account of it he lays, it could 

 neither be lluit up in vettels, nor diicerned by 

 eyes, but that it was fixed in bodies, and as it 

 were coagulated. He imagines, that in this air, 

 \vhich is very different from utmofphere air, lie* 

 the caufe of all thefe phenomena that are ob- 

 fervedin the Grotta del Cane, in fermentation, 

 t'ilerveieence, exploilon, and epidemic difeules. 

 It had been long known that the weight of me- 

 tals increaied by calcination ; but Key was the 

 firft, who ventured to account for this change 

 by the abibrption of air. 



The number and variety of furnaces, inflru- 

 ments, veflcls, and modes of operating, of this pe- 

 riod are altogether iurprifing. Luliius mentions 

 the Athanor as being long in ufe. Geberus de- 

 icribes particularly various diftillations. Agri- 

 cola was acquainted with the crucibles of Ypfen- 

 iia, and veflels oi Waldenburgh. Aludcls a lip 

 were employed, and apparatus of feveral kinds 

 for the purpofe of continued digeitions, cohoba- 

 lions, circulations, volatilisations, cementati- 

 ons, fublimations, and reverberations, were 

 contrived. 



From this view, by no means very minute, 

 that we have taken of the progrefs of chcmif- 

 try during anieraof obfcurity, we may, by com- 

 paring it with that formerly prefented of timer: 



