u8 



Exjierimenls and Inquiries reJ^eSlittg Sound and Light. 



Table xil. 



A, {hows the divifion of a monochord correfponding to each note, in the fyftem pro- 

 pofed. B, the logarithm of the temperament of each of the major thirds. C, of the 

 minor thirds. D, of the fifths; C and D being both negative. 



Thus, Sir, I have endeavoured to advance a few fteps only, in the inveftgation of fome 

 very obfcure but interefting fubjciSts. As far as I know, moft of thefe obfervatlons arc 

 new ; but, if they fliould be found to have been already made by any other perfon, their 

 repetition in a connected chain of inference may ftill be excufable. I am perfuaded alfo, 

 that at leaft fbme of the pofitions maintained are incontrovertibly confident with truth and 

 nature ; but, fhould further experiments tend to confute any opinions that I have fuggefted, 

 I (hall relinquifti them with as much readinefs as I have long fince abandoned the hypothefis 

 which I once took the liberty of fubmitting to the Royal Society, on the fundions of the 

 cryftalline lens. 



I am, &c. 



Emanuel College, Camlridge, THOMAS YOUNG. 



mjuly, 1799. 



EXPLANATION OF THE FIGURES. 



(Sec Plates IV. V. and VI.) 



Plate IV. 



Figs. I — 6. The feclion of a lleam of air from from a tube .07 inch in diameter, as 

 afcertained by m'eafuring the breadth of the impreflion on the furface of a liquid. The 

 prtflure impelling the current, was in Fig. i, i inch. Fig. 2, 2. Fig. 3, 3. Fig. 4, 4. 



Fig. 5. 7- F'g-fi, 10. 



Figs. 



