APPARATUS FOB 



Its effects, therefore, would be more strikingly dis^ 

 played, were it to carry along with it, a quantity of 

 air, than they would be, were it to force its way 

 through the tube and air in a separate fqrm. 



But, upon the whole, we must allow it to be a, 

 subject of considerable obscurity, and further trials 

 may be necessary properly to elucidate the cause. 



In concluding this subject, I may add a few ex^ 

 periments, the result of which I have not yet been 

 able to examine with sufficient care. I state them s 

 therefore, as suggestions for future examination. 



It has been found in experiments 11 and 14, that 

 the flame does not pass through a tube above 83 \ la- 

 ches long. Now, this may be explained, either upon 

 the supposition that the caloric is merely a property 

 of a quantity of air or gas, which is forced along the 

 tube by the explosion ; or upon the hypothesis I 

 have suggested, that the flame exists so far indepen- 

 dent of the air, and is rather, for the short period of 

 its motion, in an insulated form. If we hold the 

 first of these to be correct, then we will be inclined 

 to maintain, that the flame ceased to appear at the 

 bottom of a longer tube, because the velocity of the 

 air was exhausted before it could reach that point, 

 and that, therefore, its excess of caloric was given 

 out to the interior of the tube. If, again, we adopt 

 |he second hypothesis, presuming the materiality of 



