1826.] On the Comlustion of Compressed Gas. 11 1 



my paper seems ofFended that I did not notice his communica- 

 tions upon the subject of these globules, particularly as the 

 discovery was his, and was justly entitled to such consideration. 

 My silence certainly appeared uncourtly, but it was not owing 

 to ignorance of his labours, or a want of regard to him personally, 

 or as a chemist ; Prof. Silliman's merit is too well known to be 

 affected by me. 



Article VII. 



On the Combustion of Compressed Gas; being part of a paper 

 readbeforethe Literart/ andFhilosophical Society of Manchester. 

 By Mr. J. Davies, MWS. &c. &c. Lecturer on Chemistry, &c. 

 (Communicated by the Author.) 



In making, upwards of twelve months ago, some experiments 

 upon the combustion of compressed gas, I accidentally observed 

 a fact which is, I think, of rather a singular nature. 



When the aperture of the burner is, in this case, too large, 

 the flame cannot be maintained, being blown away by the rapid 

 current of the gas. When it is rather small, the flame is under 

 the best circumstances. If the aperture be further enlarged 

 without being carried to the extent at which the combustion is 

 extmguished, the flame will then be blue, noisy, and agitated, 

 atfordmg very little hght. But I found, to my great surprise, 

 that if, when the flame was in this last state, the vessel of the 

 gas was inverted, the flame was instantly changed, and instead 

 of being as I have just stated, it was steady, silent, and power- 

 ful. I have repeated the experiment frequently, and with differ- 

 ent vessels. In every instance the result has been precisely the 

 same. 



It became interesting to inquire into the cause of the pheno- 

 menon. I submit with deference the only explanation which I 

 have been able to discover. 



The gas, rarefied by heat, being lighter than the atmosphere, 

 has a tendency to move in the direction of the flame when the 

 vessel is held upright. In this case, therefore, it moves with 

 greater impetuosity than it could were the burner in any other 

 position. On the contrary, when the flame is directed down- 

 wards, it has a tendency to return upon itself. Thus the ascent 

 of the gas is promoted, and the descent retarded, by the agency 

 of the atmosphere; for the gas being rendered lighter ui the 

 way just mentioned, has a tendency to rise in the air on the 

 same principle that a cork rises in water, and its descent is in 

 like manner resisted. The fact might, perhaps, be better illus- 

 trated by conceiving air to be forced through water. If the air 

 be urged from the bottom of the vessel, it readily moves by 



