101 



connecting present perceptions with the n.nf.-ce- 

 dent ones, forms -in the brain a fund of knovyledge, 

 which increases in richness every clay. 



The imagination, being infinitely superior to a Mi- 

 chael Angelo or a Raphael, delineates in the soul a 

 faithful image of objects ; and from -divers representa- 

 tions which it composes, forms in the brain a cabinet of 

 pictures, every part of which moves, and is combined 

 with an inexpressible variety and swiftness. 



The brain of man, then, may be considered as so 

 many mirrors, wherein different portions of the universe 

 are painted in miniature : some of these mirrors ex- 

 hibit but a small number of objects; while others repre- . 

 sent almost the whole of nature. What is the relation 

 between the mirror of the mole and that of a Newton I 

 What images were there in the brain of a' Homer, a 

 Virgil, or a Milton ? What mechanism must that have 

 been which could execute such -wonderful decorations! 

 That mind which could have read the brain of a Homer 

 would have there seen the Iliad represented by the va- 

 rious exercise of a million of fibres. 



4. Of all the senses, the sight is that which furnishes 

 the soul with the quickest, most extensive, and most 

 varied perceptions : it is the fertile source of the richest 

 treasures of imagination, and it is to that principally that 

 the soul owes the ideas of beauty, and that varied unity 

 which ravishes it. 



But by what secret mechanism are -my eyes made 

 capable of communicating to me such lively, varied, 

 and abundant perceptions 1 How do I discover, with 

 so much ease and quickness, every object that sur- 

 rounds me 1 



Three humours of different density, each lodged in a 

 transparent capsule, divide the inside of the globe of the 

 eye into three parts. On the bottom is spread a kind 

 of cloth, or very fine membrane, which is only the ex- 

 pansion of a nerve, whose extremity terminates i 

 F2 



