510 APPARATUS FOR THE 



ment, occurred, with regard to the upper piece of 

 wire-gauze. 



II. When we look for the cause of these phenome- 

 na there are two explanations which at once suggest 

 themselves. The one, ascribing the whole to elec- 

 tricity ; and the other, to condensed caloric. 



The circumstances which lead to the electrical 

 explanation of the phenomena, are, 



1st, The rapidity of the result. This takes place 

 before the least vibration is conveyed to the under 

 end, as is proved by the following experiment. 



Experiment 18. — A tin cup, loosely fitted to 

 the bottom of the tube, was filled with gunpowder, 

 and a quantity of the fulminating powder was ex- 

 ploded in the usual way at the top ; in this case, 

 the motion of the flame was so instantaneous with 

 the percussion, that the gunpowder was fired be- 

 fore the vibration from the blow could act upon the 

 tin-cup. This was tried in various other ways with 

 the same result. 



2dly, The colour of the flame much resembling 

 electric light. It is slightly bluish. 



Sdly, There being some similarity in the darting 

 of the light from the bottom of the tube, and the 

 passing of an electric spark from a discharge. 



tehly, The odour resembling some of those which 

 arise from actions which have often been called 

 electrical. And, 



