l64 ON THE SONIFEROUS VIBRATIONS OF THE G ASSES. 



Tension of the Doctor Crotch remarks*, that a monochord-wire should be 

 stretched equally at bolii ends, or else it will be inaccurate. 



Chladni and The only experim^its on the sounds of the gasses, with which 



Jacquin'sexpe. I am acquainted^, and which have preceded ours, are those 

 made by professors Chladni and Jacquin at Vienna several years 



Their appara- ago. Many objections might be made to their apparatus. 



*"*• It consisted of an open organ -pipe of pewter, fixed within 



the neck of a glass receiver, furnished with a stop-cock 

 above the pipe, and a bladder on the outside. When the 

 apparatus was sufficiently filled with gas, the blast was excited 

 by pressing the bladder : this was dene over water. The tem- 

 perature during their experiments was from 54° to 5g° of Fah- 



Length of the renheit. The length of the vibrating column of air in their 

 ' pipe was about 15 cewiffwefrej, or 5'9 inches j hence it would 



pitch 1133 1 produce a sound of three octaves higher than Ut 3, or the te- 

 5 9. uor-clifFC. Their results will be mentioned farther on. 



Priestley and The experiments of Priestley and Perolle, with a bell rung by 



Perolle s exp. wheel-work, had for object only to determine the intensity with 

 which sound is transmitted by different kinds of gas, and are 

 therefore dissimilar from those which I shall now describe. 



*^P- I' 1, The receiver being exhausted till the gauge stood only 



Nitrous oxide. 044 of an inch lower than the barometer, nitrous oxide, pro- 

 duced by decomposing nitrate of ammonia, was transferred from 

 the gas-jar into the receiver of the pump in four successive 

 quantities. After each transfer, the scale of the gauge was 

 adjusted, and the movable bridge of the raonochord slid till 

 the wire and pipe were in unison. While this was doing, the 

 gauge ascended a small quantity, as we had anticipated, from 

 the absorption of vapour, by the sulphuric acid. To save 



Explanation of room, as the mode of operating was uniform, I shall dispose 

 each gas in a separate table of five columns, the first, from the 

 left, showing the nupber of successive quantities, and the 

 name of the gas j the second, the temperature ; the third, the 

 quantity of rise ; the fourth, the pressure after that rise was ob- 

 served ; and the fifth, the monochord lengths corresponding 

 with the pitch of the organ-pipe. No settled portion of time 

 was allowed for the gauge to ascend. The sound of this was louder 

 and deeper tjian that of any other gas, and in quality of tone 



• Elements of Thsrough Bass, &c. 4to. I8I2. - 



(limhe) 



