hap. 36.] Objefts and our Senjes. 365 



of the body, and more particularly to the organs of 

 fenfadon. What is the difference of ftrudture, which 

 adapts the feveral nerves to the federal organs of fen- 

 fation } we know not, nor can we determine whether 

 certain parts of the brain correfpond with the nerves 

 connected with certain organs of fenfation, and are 

 deftined to preferve the ideas received by thefe parti- 

 cular organs, or whether the whole brain is common 

 to the whole flock of our ideas and fenfations ; though 

 thefe have been fubjects of 'much Speculation, it has 

 not even yet' been ascertained, whether any material 

 imprefiion whatever takes place in the brain in confe- 

 quence of imprefiions on our fenfes j and until this 

 queftion is determined, we cannot be prepared to ex- 

 amine the other. That the brain, however, is really 

 in fome way or other the repoficory of our ideas, we 

 may venture to conclude, fmce a perfon who lofes an 

 organ of lenfation does not lofe the ideas previoufly 

 acquired by it ; and fmce perfons fometimes comphin 

 of pain, feated in the extremity of a limb of which 

 they have longTince been deprived. 



There have been of late years fome curious {pecula- 

 tions among philofophers with refpect to the material 

 caufe of inftinct in animals, and as there is fome 

 plaufibility in their reafonings, it may be worth while 

 briefly to mention the outlines of their fyftem. They 

 fuppofe that the motions of animals, commonly called 

 inftinctive, arife from a connection of the nerves be- 

 longing to different parts in the brain. In this man- 

 ner, when the young bird hears the call of its mother, 

 and opens its beak, they fuppofe this effect to be owing 

 to an original connection between the auditory nerve 

 and the nerves communicating with the mufcles em- 

 ployed in opening the bird's beak. When a new-born 

 quadruped performs the complex action of fucking, in 



con- 



