( 36S ) 



fion or eje(fllons. The effecl defcrlbed, it 

 may, confequently, be concluded, was pro- 

 duced merely by the fimple contact of the 

 water and the tin. 



I had, befides, fufficient proof that the 

 water, when included within this melted 

 metal, caufes ejedions much ftronger and 

 with a louder report. Having taken a 

 crucible containing melted tin from the fire, 

 the furface foon began to cool. I then 

 with the point of a nail made a perforation 

 through the cruft that had gathered over it, 

 which was flill thin and foft, and poured 

 on it half an ounce of water, a part of 

 which entered the perforation, when im« 

 mediately the cruft was forced up with an 

 unufual explofion, almoft all the melted 

 metal violently thrown out, and the earthen 

 crucible broken to pieces. The cooling 

 and confequent contraction of th€ cruft 

 had produced a vacuity between it and the 

 melted metal, which admitted the water, 

 but was much too confined for its expan- 



fion 



