Sect. XVI. 10. i. OF INSTINCT. 117 



There are indeed a few founds, that we very generally affo- 

 ciate with agreeable ideas, as the whittling of birds, or purring 

 of animals, that are delighted ; and forne others, that we as gen- 

 erally affociate with difagreeable ideas, as the cries of animals in 

 pain, the hifs of fome of them in anger, and the midnight howl 

 of beads of prey. Yet we receive no terrible or fublime ideas 

 from the lowing of a cow, or the braying of an afs. Which 

 evinces, that thefe emotions are owing to previous afTociations. 

 So if the rumbling of a carriage in the ftreet be for a moment 

 miftaken for thunder, we receive a fublime fenfation, which 

 ceafes as foon as we know it is the noiie of a coach and fix. 



There are other difagreeable founds, that are faid to fet the 

 teeth on edge ; which, as they have always been thought a ne* 

 cefiary effect of certain difcordant notes, become a proper fub- 

 jeer, of cur inquiry. Every one in his childhood has repeatedly 

 bit a part of the glafs or earthen veflel, in which his food has 

 been given him, and has thence had a very difagreeable fenfa- 

 tion in the teeth, which fenfation was defigned by nature to 

 prevent us from exerting them on objects harder than themfelvea. 

 The jarring found produced between the cup and the teeth is 

 always attendant on this difagreeable fenfation : and ever after 

 when fuch a found is accidentally produced by the conflict of 

 two hard bodies, we feel by aiTociation of ideas the concomitant 

 difagreeable fenfation in our teeth. 



Others have in their infancy frequently held the corner of a 

 fiik handkerchief in their mouth, or the end of the velvet cape 

 of their coat, whiifl their companions in play have plucked it 

 from them, and have given another difagreeable fenfation to 

 their teeth, which has afterwards recurred on touching thofe 

 materials. And the fight of a knife drawn along a china plate, 

 though no found is excited by it, and even the imagination of 

 fuch a knife and plate fo fcraped together, I know by repeated 

 experience will produce the fame difagreeable fenfation of the 

 teeth. 



Thefe circum (lances indifputably prove, that this fenfation of 

 the tooth-edge is owing to aiTbciated ideas ; as it is equally ex- 

 citable by fight, touch, hearing, or imagination. 



In refpcc~t to the artificial proportions of found excited by mix- 

 fical inftruments, thofe, who have early in life aiTociated them 

 with agreeable ideas, and have nicely attended to diftinguifh 

 them from each other, are faid to have a good ear, in that coun- 

 try where fuch pi-oportions are in fafhion : and not from any 

 fuperior perfection in the organ of hearing, or any mftin drive 

 fympathy between certain founds and paffions. 



I have obferved a child to be exquiiitely delighted with muilc, 



rid 



