1 20 'On Attra^ion and Repulfton. 



face of a pond be ftruck with a (lick, numerous 

 globules of water roll over without breaking, 

 v/hilft they pafs feveral yards from the place 

 where the water was ftruck. In thefe cafes of 

 apparent repulfion I fuppofe that every drop of 

 water furrounded with air becomes globular by 

 the cohelion of its own particles, and unlefs its 

 weight or contadl with other furtaces be fufficient 

 to overcome its cohefion, and difplace the air 

 adhering both to the drop and to the furface 

 which it falls upon, it retains its form and cannot 

 unite with them. 



Soap bubbles will roll over or rebound from 

 a carpet, though they be filled with fmoke, which 

 makes them heavier than when blown with clear 

 air. Alfo pins may be thruft through them, and 

 even the fmall end of a tobacco pipe, fo as to 

 blow a fmaller bubble within the larger without 

 its immediately breaking : but if a bubble fall 

 upon a fmooth plain furface, it inftantly breaks. 



I have fometimes been amufed with blowing 

 bubbles with inflammable air, and by attaching 

 to them a fmall circle of paper and fine thread 

 or raw filk, could hold them fufpended in the 

 air for a confiderable time. Another amufing 

 experiment was to fix to the inflammable air- 

 bubble a fmall flip of nitred paper, to the fide 

 of which and near the top a grain of gun- 

 powder was annexed. The fmall end of the 



paper 



