ON THE THEORY OF COMPOUND SOUNDS. 39 



VIII. 



Reply to Dr. Youn g's Letter on the Theory of Compound Sounds. 

 In a Letter from Mr. John Go ugh. 



To Mr. NICHOLSON. 

 S I R, 



Y OU have publifhed Dr. Young's anfwer to my remarks on On the proper 

 the theory of compound founds; and I doubt not but you will/P 11 " of comro- 

 ivith equal impartiality, find a place for the following reply in 

 your Journal. When a controverfy is conducted with good 

 humour, it affords amufement; and when it furnifhes frefli 

 facts, or places the fubject of difpute in a new point of view, it 

 proves inftructive. Dr. Young's anfwer poflefles both thefe 

 qualities ; and it is my duty to imitate him, at leaft in the ob- 

 servance of the former. Having now completed what may be 

 called the introduction of the prefent letter, I will, with the 

 permiffion of Mr. Nicholfon, make a iew remarks upon the 

 principal objections contained in the anfwer under confidera- 

 tion. The Doctor obferves, that my theory of vibrations in an Explanatory re- 

 elaftic fluid differs as widely from Dr. Smith's hypothecs as marks « 

 from his own conceptions relating to the fame operations : but 

 he will probably recollect, that I profefs to maintain compound 

 founds to be mixtures of elementary founds, not aggregates by 

 coalefcence ; in other words, I undertake to defend Dr. Smith's 

 propofition, as a fundamental maxim both of harmonics and the 

 general philofophy of founds. When the queflion is thus pro- 

 perly ftated, the engagement I undertake to perform cannot in 

 any fenfe oblige me to fupport the collateral arguments, with 

 which Dr. Smith thought proper to elucidate his propofition, 

 perhaps unfortunately. For if the pofitive maxim, viz. that That compound 

 compound founds are mixtures, be eftablilhed, the defign of [°™f are miX ~ 

 jny effay is accompliflied : and as Dr. Young does not contro- 

 vert the leading conclufions of this paper, I may fairly fuppofe 

 he admits them, but am at a Iofs to underiland in what manner 

 they favour his fide of the queflion ; for if my inferences be 

 juft, compound founds are not formed by coalefcence, which aid not formed 

 is the point in debate. I do not pretend to fay precifely what y coa e v ' eoce ' 



would be the confequence of conducting a number of founds 



through 



