S5 ; 

 IV. 



On the Musical Modes of the Hindus: written in 1784, 

 and fmce much enlarged.— By the President. 



MUSICK belongs, as a Science, to an interefting part of natural, 

 philofophy, which, by mathematical deductions from conftant phe- 

 nomena, explains the caufes and properties of found, limits the number o£ 

 mixed, or harmonick, founds to a certain feries, which perpetually recurs,, 

 and fixes, the ratio, which they bear to each other or to one leading term % 

 fouts, confidered as an Art, it combines the founds, which philofophy diftin- 

 guifhes, in fuch a manner as to gratify our ears, or affect our imaginations, 

 or, by uniting both objects, to captivate the fancy while it pleafes the fenfe,. 

 and, fpeaking, as it were, the language of beautiful nature, to raife corref- 

 pondent ideas and emotions in the mind of the hearer : it then, and then 

 only, becomes what we call a fine art, allied very nearly to verfe, 

 painting, and rhetorick, but fubordinate in its functions to pathetick poetry, 

 and inferior in its power to genuine eloquence. 



Thus it is the province of the philofopher, to difcover the true direction 

 and divergence of found propagated by the fucceffive compreffions and ex- 

 panfions of air, as the vibrating body advances and recedes ; to (how why- 

 founds themfelves may excite a tremulous motion in particular bodies, as 

 in the known, experiment of inflruments tuned in uniibn ; to demonflrate 

 the law, by which all the particles of air, when it undulates with great 

 quicknefs, are continually accelerated and retarded ; to compare the num- 

 ber of pulfes in agitated air with that of the vibrations, which caufe them: 

 to compute the velocities and intervals of thofe pulfes in atmofpheres of dif- 



