CONTENTS OF VOL. I. XX1U 



Page. 



2. Sense of Heat. 



Its peculiar characters. Information which it commu- 

 nicates. 171 



3. Sense of Light. 



Structure of the Eye. Coats of the Eye, sclerotica. 

 cornea, choroides, ciliary ligament and processes, 

 uvea, iris, pigmentum nigrum. Humours of the 

 Eye, vitreous, crystalline, and aqueous. Nerves 

 of the Eye, Optic nerve, Retina. Muscles of the 

 Eye. Glands, lachrymal, Meibomian, and carun- 

 cula lachrymalis. Coverings of the Eye, eye-lids, 

 nictitating membrane, conjunctiva, eyebrows. Sim- 

 ple and compound eyes. . . 172 



Functions of the Eye. Focus. Why objects are not 

 seen inverted. Objects seen at different distances. 

 Diurnal and nocturnal Animals. Albinoes. Single 

 vision with both eyes. . ] 82 



Knowledge procured by the sense of Sight. Colour 

 of bodies, their direction, magnitude, distance, sur- 

 face, and motion. Apt to deceive. Painting. 193 



4. Sense of Hearing. 



Structure of the Organ. Internal Ear. Labyrinth, 

 auditory nerve, tympanum, Eustachian tube. Ex- 

 ternal Ear, concha. . . 199 



Knowledge procured by Hearing. Sound informs us of 

 the distance, position, and velocity of bodies,, even 

 their composition. . ... 203; 



5. Sense of Smell. 



Structure of the Organs. Nose, septum narium, ol- 

 factory membrane, nasal mucus, olfactory and nasal 

 nerves, Sinuses. . 206 



Functions of the organ of smell. Odours. Knowledge 



communicated, Useful in selecting food. . 207 



