168 



ON THE SONIFEROUS VIBRATIONS OF THB GASSES. 



1. Azotic gas - 



2. - - - - 



3. - - - - 



(A little air 

 added.) 



Pitch. 



Exp. 11. 



Su'pLuretted 



hidrogen. 



Addeci common air 



60 



[•10 



730 



— 



•10 



14-50 



— 



■10 



21-55 



•— 



•15 



2775 



— 





29-40 



•2210 

 •2210 

 -2215 

 •2230 



•2225 



A mean of the four gives the sound a little more than a 

 comma more acute than the sound of common air. 



11. Sulphuretted hidrogen, obtained from powdered sulphu- 

 ret of iron, a little water, and weak muriatic acid, gently heated 

 in a glass retort, and collected over water. A large quantity 

 of the gas was absorbed by the water in the pneumatic trough. 



1 . Sulphuretted hidrogen 



2. ----- - - 



4. 



62'5 



•3p 



6-88 



61-5 



•68 



13-74 



61 



•30 



20 82 



58-5 



•50 



27-12 



•0000 

 •2035 

 •2070 

 •2075 



The least 

 norous of 

 gasses. 



Its pitch. 



Exp. 12. 

 Hidrogen. 



This is the least sonorous of all the gasses that we have tried. 

 The sound was hardly appreciable after the second tranfer of 

 gas ; and even after the third it was impossible to maintain a 

 continual sound by the most rapid action of the bellows. The 

 pitch of this gas, from a mean of the three lengths, is not quite 

 a minor tone higher than that of common air, but is more than 

 a major semitone. At the end of this experiment, the sulphu- 

 ric acid placed in the receiver had a froth on its surface about a 

 quarter of an inch high, and of various metallic colours. And 

 we observed, that a pait of the oily matter produced in the 

 sixth experiment, and which so obstinately adhered to the plate, 

 could be much more easily wiped oft". 



12. Hidrogen gas, obtained from water, bits of zinc, 

 sulphuric acid. 



61 5 



and 



1 . Hydrogen gas 



2. - - - - 



3. - - - - 



4. - - - - 



10 



rg6 



•111 



08 



15-36 



•111 



14 



22-72 



•111 



- - 



28-86 



•111 



Its pitch. The sound v/as weak, and more than an octave and comma 



above that of air. On working the pump till the pressure of 



Breath added, the gas was 14^28, and adding breath till the pressure was again 

 28 86, the sound of the mixture agreed with '1815 of the mo- 

 nochord 3 and the gauge soon rose again 0^2 . 



14. Light 



