378 INDEX. 



in one country, and deposited on another, 303. In Arabia 

 and Africa, described, 309. 



Tendrac, an animal less than a mole, different from the hedge- 

 hog, and a different species; description; grunt like hogs, 

 and love to be near water ; they multiply in numbers ; sleep 

 several months ; its flesh a great delicacy with the Indians, 

 iii. 209. 



Tercel, name falconers give the male bird of prey, and why, 

 iv. 68. 



Terrier, a small kind of hound, iii. 15. 



Teuthys, a prickly-finned abdominal fish ; description of it, 

 v. 123. 



Testaceous substances, in variety on the tops of mountains, 

 and in the heart of marble, i. 14. 



Thales, the philosopher, held all things to be made of water, 

 i. 144. 



Thames water, and that of the Indus, most light and whole- 

 some, i. 143. 



Theories of the earth, those of the most celebrated authors, 

 i. 18. 



Theory of evaporation, for the formation of clouds ; other 

 theories upon that subject, 313. Beautiful theory of 

 sympathy, of Father Malbranche, upon monstrous produc- 

 tions, ii. 99. 



Thermometer, measures heat and cold by a fixed standard ; 

 description, i. 152. 



Thoracic fish, that which has the ventral fins directly under 

 the pectoral fins, v. 117. 



Throat of the great Greenland whale is so narrow, that any 

 animal larger than a herring could not enter, v. 40. But 

 that of the cachalot can with great ease swallow an ox, 52. 

 That of the shark most amazing, 67. 



Thrush, a slender billed bird of the sparrow kind, iv. 255. Its 

 distinction from all of the kind ; its song very fine ; the 

 largest of the tribe with a musical voice ; its food, 260. 



Thumb-footed shell-fish, testaceous, described, v. 249. 



Thunder, Ulloa heard it rolling beneath him, when upon the 

 Andes, i. 130. Its cloud always moves against the wind, 

 300. A sound produced by the opposition of two clouds, 

 and continued by reverberated echo, 317. Thunder clears 

 the air, and kills insects noxious to vegetation, 318. 



Thyroid (cartilage) forms a lump upon the wind-pipe in men, 

 not seen in women, i. 429. 



Tides, the most obvious motion of the sea ; with Pliny, were 

 influenced partly by the sun, and in a greater degree by 

 the moon ; Kepler first conjectured attraction the principal 

 cause of them ; the precise manner discovered by Newton ; 

 high tides happen at the same time on opposite sides of the 

 globe, where waters are farthest from the moon ; solar and 



