( 37° ) 



dlately on the tin, but on the pulverulent 

 pellicle with which it is invefted by oxyda- 

 tion, fince I carefully removed it as often 

 as it was formed. 



Melted lead exhibited the fame appear- 

 ances with the tin, and fimilar irregularities, 

 except that its explofions w^th water were 

 not fo frequent, nor, as it appeared to me, 

 fo ftrong. 



I fliall not here enquire why the water 

 in the furnace exhibits no evaporation of 

 any kind, nor boils till after fome inftants 'y 

 whereas, when the experiment is made in 

 the open air, the ebullition and evaporation 

 follow immediately that the water touches 

 thefe two metals, now fomewhat cooler : 

 nor why, Vvhen the water falls on lead and 

 tin, it explodes with a loud noife, while no 

 fuch explofion happens with copper and 

 iron. Such refearches, to be properly made, 

 require other experiments, which would 

 lead me too far from my fubjecl. It ap- 

 pears to me preferable to proceed imme- 

 I diately 



