( 338 ) 



which a plate of filver was gilt by a like 

 efFed: of fire on gold. I concluded, there- 

 fore, that the globules and the other traces 

 of enamel congealed on the fides of the 

 matrafs were the refult of the fublimation 

 of the enamel itfeif at the time it Was ex- 

 pofed to the moft violent heat, 



A- doubt however remained, which it was 

 neceflary to remove. It feemed not impof- 

 fible that, in putting the pulverifed enamel 

 into the matrafs, fome fmall portion of the 

 powder might have adhered to the fides or 

 the fwelling in the neck, and afterwards 

 have been melted by the adion of the fire. 

 But this doubt was completely removed by 

 obferving the fame appearance on the fides 

 and neck of another matrafs, in which an 

 equal quantity of the fame enamel had been 

 placed, not in powder, but in pieces. 



This obfervation, which confirmed me in 

 my opinion that the ebullition of fubftances 

 fufed in matrafTcS was a confequence of 

 their vaporifation, determined me to make 



a general 



