BOOK III. Of the galaxy, or milky way, 148. Of comets and shooting fires, 149. Of lightning, thunder, hurricanes, and whirlwinds, 150. Of clouds rain, snow, and hail, 151. Of the rainbow, 152. Of meteors which resemble rods, 153. Of winds, 154. Of winter and summer, 154. Of the earth, its nature and magnitude, 154. Of the figure of the earth, 155. Of the site and position of the earth, 155. Of the inclination of the earth, 155. Of the motion of the earth, 156. Of the zones of the earth, 156. Of earthquakes and their cause, 157. Of the sea, of what it is composed, and why it has a bitter taste, 158. Of the ebbing and flowing of the sea, 159. Of the halo, or circle round a star, 160. BOOK IV. Of the overflowing of the Nile, 160. Of the soul, 161. Whether the soul be a body, and what is its nature and essence, 162. Of the parts of the soul, 162. What is the principal part of the soul, and in what part of the body does it reside? 163. Of the motion of the soul, 163. Of the soul’s immortality, 164. Of the senses, and their objects, 164. Whether what appears to our senses and imaginations be realities, 165. How many senses are there? 165. How the conceptions of the mind are received from the senses, 166. What is the difference between imagination (φαντασία), imaginable (φανταστόν), fancy (φανταστικόν), and phantom (φάντασμα)? 167. Of our sight, and by what means we see, 168. Of the images presented to the eye in mirrors, 169. Can darkness be visible to us? 169. Of hearing, 170. Of smelling, 170. Of taste, 170. Of the voice, 171. Whether the voice is incorporeal? what is it that gives the echo? 172. By what means the soul is sensible, 173. Of respiration or breathing, 173. Of the passions of the body, and whether the soul sympathizes? 175.