18 ANATOMY AND PHYSIOLOGY. 



principle that gives all our sensation, when much affected by the 

 operations of the mind, becomes weakened, if the intellectual 

 faculties are acted upon by reflection, or impressions of any kind 

 to excess. It is not surprising, therefore, that debility of the 

 system is induced from too much thought and intense study. 



The creation abounds with objects fitted to yield the most refined 

 entertainment The sun impurples the robe of morning ; and stars 

 bespangle the curtains of night. Flowers of silver whiteness, and 

 golden lustre, enamel the ground. Fruits of every radiant hue, and 

 every delicious taste, hang dangling on the boughs, but all in vain 

 to us, if kind providence had not endowed us with the powers of 

 sense ; without which the breath of fields must lose its reviving 

 fragrance, the whispering grove must degenerate into sullen 

 silence, and nature's book of knowledge, all fair and instructive, 

 would be no better than a vast unmeaning blank ; but providence, 

 profusely gracious, has presented us with senses., the inlets of vari- 

 ous delights, innumerable pleasures, and the most valuable advan- 

 tages. 



What though we trace each herb and flower 



That drinks the morning dew ; 

 Did we not own Jehovah's power 



How vain were all we knew. 



HANDEL. 



In an elevated situation, like a sentinel on a watch-tower, high in 

 the head is placed the eye, bright and conspicuous as a star in the 

 brow of evening, commanding the most enlarged prospects. Con- 

 sisting only of simple fluids, inclosed in their tunics, it conveys to 

 our apprehension all the graces of blooming nature, and all the glories 

 of the visible heavens. An image of the hugest mountain, and a 

 transcript of the most diversified landscape, enters the small circuit 

 of the pupil. Its tender nature is guarded with most solicitous care 

 it is intrenched deep in the head, and barricadoed on every side 

 with a strong fortification of bones. To guard its polished surface 

 from the smallest fly, it is defended by two substantial curtains 

 hung on a most slender cartilaginous rod : these are closed in 

 sleep, and, on the approach of any danger, fly together quicker 

 than thought. They are lined with fine moist sponges, as it were, 

 which lubricate the eye-balls, and keep them fit for unwearied 

 activity. The eye-lashes keep off the smallest mote, and moderate 

 the too potent rays of the sun. The brows also break the force of 

 the light, and prevent the perspiration from offending them. The 



