GENERAL VIEW OF THE HUMAN SYSTEM. 19 



arches are so finely colored, and so elegantly turned, that they set 

 off the whiteness of the forehead, and bestow additional grace on 

 the whole countenance. 



The ear consists of the porch, or semicircular lodge, which 

 stands prominent from the head, and is not soft and sinking as 

 flesh, lest it should absorb the sound, rather than promote the reper- 

 cussion ; not hard and stubborn as bone, lest it should be painful 

 when we repose, but is cartilaginous, with a tight expansion of 

 skin, and wrought into irregular bends and hollows, which collect 

 the sound and transmit it to the finely stretched membrane, the 

 tympanum^ so called because it resembles a drum in figure and 

 use ; being a fine skin expanded upon a circle of bones, and over a 

 polished reverberating cavity. It is affected by the vibrations of 

 the external air, as the covering of the drum is by the sticks. It 

 is also furnished with braces, which strain or relax at pleasure, and 

 accommodate its tension either to loud or languid sounds. 



The avenue of the ear is secured by a viscous and bitter matter 

 from the approach of insects. The winding labyrinths and the 

 sounding galleries, etc., are all instrumental to the power of hear- 

 ing, and are beyond description curious. The auditory tube softens 

 and qualifies rushing sound, lest if the incursion were direct, it 

 might by its impetuosity injure the delicate expanse of the tym- 

 panum ; while, however, this is designed to moderate, the inner 

 parts are prepared to heighten and invigorate the sounds, by means 

 of an echo. Amazingly nice and exact must be the tension of the 

 auditory nerves, since they correspond with the smallest tremors 

 of the atmosphere, and easily distinguish their most subtle varia- 

 tions. They 'give existence to the charms of music, and reciprocate 

 the rational entertainments of discourse. The eye perceives only 

 the objects before it, but the ear warns us of transactions on every 

 side. The eye is useless amid the gloom of night, but the ear 

 admits her intelligence through the darkest medium. The eye is 

 always on duty in our waking hours, but the ear is always ready 

 to communicate any pleasure or danger. 



Smelling conveys, by an expansion of the olfactory nerves, an 

 idea to us of the quality of the particles wafted in the air. The 

 nostrils are wide at the bottom, that a large quantity of effluvia 

 may enter, narrow at the top that they may there act in a more 

 vigorous manner. Fine beyond all imagination are the steams which 

 exhale from fetid or fragrant bodies. The microscope that can disco- 

 ver millions of animalculae in a drop of putrefied water, cannot 



