INDEX. 315 



stances of it ; by birth a Thracian ; from being a simple 

 herdsman he rose by the gradations of office, until he came 

 to be Emperor of Rome ; was above nine feet in height, and 

 the best proportioned man in the empire ; was killed by his 

 own soldiers while sleeping, i. 442. 



May-bug, or Dor-beetle, described, vi. 148. See Beetle. 



Mechanism, which regulates the number of our years, admits 

 no change in its laws, and can be affected only by long 

 fasting, or great excess, ii. 66. 



Medauro, the brass helmet dug up there fits a common man, 

 yet is allowed to have been left there at the overthrow of 

 Asdrubal, ii. 116. 



Mediterranean Sea, always receiving and never discharging 

 water, is no way fuller than before ; in what manner some 

 account for this, i. 221. Water-spouts seen in it ; descrip- 

 tion of them by Tournefort, 331. Solutions offered for this 

 phenomenon by M. Buffon and Dr Stuart, 334. This sea 

 one of the smoothest and most gentle in the world, 229. 



Medusa, name given by Linnaeus to a small insect, thought 

 the simple food of the great Greenland whale ; walfischoas, 

 the name given to it by the Icelanders, v. 4-0. 111. 



Membrane, the nictitating membrane in birds ; veils the eye 

 at pleasure, whilst the eyelid continues open, iv. 8. 



Menstruum, that body which is most fluid and penetrating, is 

 likely to be the menstruum of one less so ; Marriotte's ex- 

 periment shows that water will act as a menstruum upon 

 air ; cold diminishes the force of menstruums, and often 

 promotes evaporation, i. 314. 



Merlin, the smallest of the hawk or falcon kind, scarce larger 

 than a thrush, displays a degree of courage rendering him 

 formidable to birds far above his size ; kills a partridge or 

 a quail at a single pounce from above, iv. 100. 



Metals, the richest, in their native state, less glittering and 

 splendid than useless marcasites, i. 67. Those trades that 

 deal in their preparations, always unwholesome, 278. All 

 pieces swallowed by animals lose part of their weight, and 

 often the extremities of their figure, iv. 45. 



Meteors, between the tropics, and near the poles, assume 

 dreadful and various appearances, i. 320. In those coun- 

 tries where the sun exerts the greatest force in raising 

 vapours, there are the greatest quantity of meteors, 321. 

 One of a very uncommon kind seen by Ulloa, at Quito, 

 323. 



Method, the principal help in natural history : without it little 

 progress made in this science, ii. 135. The most applaud- 

 ed of classing animals, 138. The author's method of class- 

 ing them, 143. That of describing all things by words alone, 

 a fault that has infected most of our dictionaries, and bodies 

 of arts and sciences: Mr Locke has observed, that the 



