113 



judge it to be, without actually' knowing the truth, the 

 smaller we must also suppose it. Of this diminutive size, 

 and bearing a just proportion to each other, as in a painting 

 accurately executed according to the rules of perspective, all 

 objects within the field of vision must probably appear to a 

 child at the period alluded to; no prominence observable; 

 but the whole consisting of a flat plane diversified by shades 

 and colours. Though it may be doubtful whether this pic- 

 .ture does not very early assume the form of a concave hemis- 

 phere ; similar in every respect, but in magnitude, to the 

 area comprehended by more perfect vision, but so confined as 

 to appear within tangible distance of the hand of the infant. 

 The visual powers command an equal extent in all direc- 

 tions ; and if, as a necessary consequence, the boundary of 

 vision presents to the adult an immense sphere, it must in 

 like manner present a sphere of reduced dimensions to the 

 infant, whose powers of vision likewise extend in all direc- 

 tions, but only, in his conception, to the distance of a few 

 inches. 



Nearly at the distance which the infant has first learned to 

 assign to objects, is in all probability established the barrier 

 between distinct and indistinct vision : all things within it 

 appearing larger than they actually are, and encreasing in 

 size and indistinctness as they approach the eye; and all be- 

 yond it diminishing in size the farther they recede from it, 

 till they are also involved in obscurity and at length lost to 

 sight. A pin not an inch long, if brought close to the pupil, 



VOL^XII. Q 



