ON THE SOUND PRODUDED BY HIDROGEN GAS* 131 



great variety of fuch jars on the table, many different tones 

 were produced on the very firft day, by applying jars of dif- 

 ferent capacity and thicknefs. 



1 am, SIR, 



Your's refpe&follyi 



B. HIGGINS. 



Percy Hotels Jan. \2 } 1802* 



The caufe of the curious phenomenon here defcribed feems Speculation on 

 difficult to be clearly afcertained. As it is univerfally ad- lts cau e * 

 initted that found is caufed by undulations, that is to fay, 

 alternate condenfations and rarefactions of the air, or fome 

 more fubtle fluid, we are naturally led to an intention and 

 remiflion of the flame of the hidrogen. It is probable that all 

 flame undulates. The flame of a candle is faid to dance Caufe why the 

 when this effea is moil remarkably evident. I fuppofe the ^° f a £andIe 

 fupply of oily vapor enlarges the flame, until its furface be- 

 comes fo extenfive, as to abforb oxigen in greater quantity 

 than the fuel can be fupplied to keep up a combuftion of that 

 iize : it therefore becomes lefs, until by the diminution of 

 furface, the due proportion of oily vapor, compared with the 

 oxigen, again exceeds. And in this way we may form a 

 notion of perpetual undulations of fize. If thefe changes 

 were rapid and ftrong enough, the air would be ftruck by 

 them into fonorous undulations. In the fame manner perhaps A chirping noife 

 we may account for the loud chirping noife I have obferved £ r0 u * 

 to be produced by the inflamed drops of tallow which fall 

 from a candle held nearly upfide down at five or fix feet from 

 the ground. 



K 2 X.—Dcfcription 



