f>f ChlaJni and 'Jacqu'in, 285 



Chladiii's experiments, therefore, feem to contradift thofe 

 made by Prieftley and mvfelf. To reconcile them, it will 

 no doubt be ("aid that Chladni and Jacquin employed a 

 wind-inftrument, and that my experiments and thofe of 

 Prielllcv were made with metallic bodies rendered fonorous 

 by percuflion. But whence does it happen that thofe fluids, 

 fome of which lower the found of a pipe one-third, while 

 another makes the found of the fame pipe from nine to eleveix 

 tones higher, have not power to alter the tones of a metallic 

 body in any fenfible degree ? I fhall here oiFcr a few remarks 

 which feem to arife from thefe general obfervations. 



In a mixture of oxygen and azote, in the fame proportions 

 as la the atmofpheric air, found is the fame, according to 

 Chladni and Jacquin, as in the latter medium ; but they 

 add, if the mixture of thefe two gafes is not complete, the 

 found is quite difcordant. What ! do oxygen and azote af- 

 ford each of them the fame found ? and does an incomplete 

 mixture of them produce a difcordant found? It will no 

 doubt be replied, that azote and oxygen do not give the fame 

 tone as atmofpheric air; but, in theatres, ball-rooms, con- 

 cert-rooms, &c. where a great number of fpeiSlators are 

 affembled, and where there is a fufficient quantity of car- 

 bonic acid, which docs not combine with the air of the 

 atmofphere, has it ever been obfcrved that wind inftru- 

 ments were difcordant ? If an incomplete mixture of at- 

 mofpheric air with gas, which lowers the found one third, 

 does not render the founds difcordant, how can we perfuade 

 ourfelves tha,t a mixture of two gafes, which caufe a falling 

 of only half a tone, fliould occafum a found altogether difcord- 

 ant, merely becaufe the portions of the gafes are completely 

 tnixcd, while the admixture of fonie other particles is much 

 Icfs complete ? 



The above authors inform us alfo, that in hydrogen eas 

 the found rifes nine or eleven tones. Here there can be no 

 medium. Either the found produced in the hydroc^cn is 

 ftjarpcr by nine tones, and in that cafe the elevation ought 



ij not 



