I So THE HUMAN BODY. 



a lark or a quail hiding in the ploughed fields, although it so 

 closely resembles that of the soil. But if we should suppose 

 them endowed with sensitive faculties, useless within the 

 limits of their instinct, could we find anything in animals 

 more perfect than the organs to which man owes the prodi- 

 gies of painting? We must, however, distinguish here between 

 that which pertains to the visual apparatus, and that which 

 proceeds from the intellect. The eye perceives the tints 

 which nature offers in almost infinite variety; the mind com- 

 pares them, and recognizes the elementary colours of which 

 they are composed; the eye reflects in turn the model, the 

 palette, and the picture; the mind perceives the relation of 

 shades, and combines them in such a manner, that by 

 mingling or contrasting them such a result is produced as 

 conforms to the first impression; but in order that an artist 

 may judge whether red or blue predominates in a violet tint, 

 in order to appreciate the shade, the retina must transmit it 

 to the brain in its purity. 



At the manufactory of the Gobelins, we see the wools used 

 in the fabrication of the tapestries arranged according to their 

 shades. The number of these shades exceeds 28,000, and 

 yet when we compare two approximate shades we distinguish 

 them with facility, and perceive the interval which separates 

 them. 



The people who live in the country, seamen, and especially 

 men living in a savage state, generally have sharper sight 

 than the residents of cities. May not the habit of seeking to 

 distinguish objects at a distance give the eyes a power which 

 is not acquired when they always act within a limited hori- 

 zon? Without assimilating exactly the effects of exercise on 

 the eye to those which result from exercise of a muscle, we 

 are justified in thinking that an almost incessant accommo- 

 dation to great distances must influence the eye in that 

 respect, and if, as is very probable, the accommodation takes 

 place by the contraction of muscular fibres, the explanation 

 of the increased range of the eye from exercise is very simple; 

 but facts are wanting which verify and measure this increase 

 in individuals. There is no doubt, however, that men from 

 whom the horizon is habitually distant distinguish certain 



