ON THE SONIFEKOUS VIBRATIONS OF THE GASSES. , l67 



Here the lever of the bellows breaking, we had to begin this 

 experiment anew. The gas was pumped into a bladder and 

 used again. 



1. Oxigen gas - - - | 6g-5 [ -05 I 8*26 I '23250 



2. J I -25 I 15 61 I -23600 



3. - I '40 22 61 -23800 



4. I I - - I 29 98 I •23875 



A mean of seven gives the pitch a little more than a minor Its pitch, 

 semitone graver than that of air — Chladni found it to be a semi- 

 tone or nearly a tone ; and our former experiments, with the 

 little open pipe^ make it not quite half a comma. 



8. Nitrogen gas, obtained from small pieces of lean muscular Exp. 8. 

 flesh (beef) and weak nitric acid, gently heated in a glass re- Nitrogen gas. 

 tort. The gas stood over water for twelve hours before it was 

 used. 



1 . Nitrogen gas 



2. - - - - 



3. - - - - 



4. - - - - 



68 

 68-5 



•08 I 772 I -2185 

 •14 I 1520 I 2250 

 05 I 2295 -22/5 

 3000 -221^0 



This gas produced a very weak, dead sound 3 the same in its pitch, 

 pitch as common air. Chladni found it almost a semitone 

 graver. 



9. After working the pump till the pressure wa^ only 22^5, Exp. 9. 



oxigen gas was added to the nitrog-en in the receiver, till the ^'^'5'"^&^'^ *°<* 

 00 a } oxigen. 



pressure was again 300, when the sound of the mixed gass«s 

 was 0*2335, or almost three commas below the sound of common 

 air. Chladni found that a mixture of these two gasses gave a 

 sound in unison with that of atmospheric air, being more acute 

 than either gas alone. " But before the mixture of these fluids 

 had become homogeneal by repeated pressions of the bladder, 

 the sound was not appreciable, because the vibrations could not 

 be isochronous." (Chladni, § 67.) 



10. Azotic gas, procured by setting fire to a piece of phos- ^-^P- ^o. 

 pborus in atmospheric air confined over water. It was inflamed " 

 with a burning lens. Before the gas was used it was left in 

 sunshine, over water, for several hours. 



