74» »N THE GRAVE HARMONICS. 



tween the teeth ception of a grave harmonic, and the fenfation of a ringing in 

 with abeafif * ^ e ears ' * s in g en » ous anc * probable ; and I can mention a fin- 

 another found gular experiment in confirmation of his opinion. If a tuning 



^anfmi U t"ed 0n ** fork ' faint ty vibratIn g> be held between the teeth, and a found 

 through the air ; nearly approaching to the fame note be tranfmitted through 

 the air, the beating will be nearly as diftinft as if both founds 

 whence it isjn- arrived through the fame medium. From this circumftance, 

 mate direction now ever, I only infer that all founds enter the ultimate organ 

 of all founds is of hearing nearly enough in the fame direction to produce an 

 nearly the fame. alternate intenfl0n and re miffion. 



The grave har- I allow that fueh a found differs from primitive founds in its 

 from primitive want of appropriate direction, and in its mode of propaga- 

 founds ; tion. The daily tide at Batfha in Tunquin neither comes from 



real thanwrn- 5 tne ea ^ nor ^ rom tne wej ^* but lt ls as n iucn a real tide as the 



pound tides, Sec. grave harmonics are real founds. If any perfon (hould infift 



that the phenomenon is not a tide, but an alternate elevation 



and depreffion of the water only, and that it exiffo only in the 



fenfations of the obfervers, and not in the fea, I mould be 



very little difpofed to enter into arguments with him on the 



fubje6l. 



Remarks on the With refpect to the communication of my remarks to the 



of^hiiofopWc"! Manchefter Society, I beg leave to reply, that if I thought a 



papers. Philof. paper of permanent importance to the extenfion of fcience, I 



?inci!iMemoirs. mou ^ confider myfelf as bound by my duty to the Royal So- 



Joumals. ciety and to pouerity, to offer it for infertion in the Philofo- 



phical Tranfaftions ; but if it were of a mere fuperficial and 



temporary nature, I mould think it fufficient to publifh it in a 



refpedtable literary Journal. I do not mean any difrefpeel to 



provincial focieties, but many papers have appeared in the 



volumes of the Manchefter Memoirs, which would perhaps 



have been more fuitably placed in thofe of the Philofophical 



Tranfa&ions. 



Your obedient, 



humble fervant, 



THOMAS YOUNG. 

 /an. TO, 1803. 



IV, Experiment 



