26 On the Sounds produced by Flame in Tubes. [1818. 



produced sounds similar to those obtained from a jet of flame 

 in a tube. 



Having thus endeavoured to account for the phenomenon of 

 sounds produced by jets of flame, in tubes and other vessels, I 

 shall notice shortly the combustible bodies I have tried. Car- 

 bonic oxide, olefiant gas, light hydrocarbonate, coal-gas, sul- 

 phuretted hydrogen, and arseniuretted hydrogen, were burned 

 at the end of a long narrow brass tube rising up from a trans- 

 ferring jar placed under pressure in a pneumatic trough. ./Ether 

 was burned from the end of a tube fixed in a flask containing a 

 small quantity which was heated ; but a better method, and 

 one I afterwards adopted, is to pour a little aether into a blad- 

 der, and then force common air in ; so much aether rises in 

 vapour as to prevent the mixture being detonating, and it may 

 be pressed out and burnt at the end of a tube. All these were 

 very successful. Alcohol was more difficult to manage from 

 being less volatile; but it succeeded when raised in vapour 

 from a flask and burnt at a tube. In trials made with a wax 

 taper, no distinct tone could be produced ; but when the tube 

 was made very hot, so as to assist the current through it, 

 something like the commencement of a sound was heard at the 

 moment the taper was blown out by the current. 



Hydrogen is by far the best substance by which to produce 

 these tones ; and its superiority depends upon the low tempe- 

 rature at which it inflames, the intense heat it produces in com- 

 bustion, and the small quantity of oxygen that a given bulk of 

 it requires. It is in consequence less easily extinguished by 

 the current than other gases, the current formed is more power- 

 ful and rapid, and an explosive mixture is sooner made. With 

 gases producing little heat by combustion, and therefore occa- 

 sioning but a feeble current, the effect is increased by first 

 heating the tube at a fire, and when not heated previously, the 

 tone is perceived to improve as the tube becomes hot from the 

 flame playing in it. 



Some variations of the form of the vessel enclosing the flame, 

 and the material used, have been mentioned. Globes from 

 7 to 2 inches in diameter, with short necks, give very low 

 tones : bottles, Florence flasks, and phials have always suc- 

 ceeded : air-jars from 4 inches diameter to a very small size 



