CROTALUS HORRIDUS. 



There is also the Wood Rattlesnake, Crotalus dryinus, 

 which is of a paler color than either of those previously men- 

 tioned, and more particularly distinguished by its having a 

 much longer rattle. The Ground Rattlesnake, Crotalus mili- 

 arius, is a small species, which inhabits the Southern and 

 Western States of America. It has but two or three rattles 

 on the tail, and is much dreaded, as its small size and the 

 slight noise of its rattle render it more liable to be overlooked. 



The remains of an extinct genus of serpents, indicating 

 species of from ten to twenty feet in length, have been dis- 

 covered in the Eocene tertiary formations in Suffolk, Kent, 

 and Sussex, England. (See Owen's paper in the Geological 

 Transactions, 2d Series, Vol. VI. p. 209.) 



In antiquity the serpent played an important part. By 

 some nations it was regarded as the emblem of cunning, de- 

 ceit, and wickedness (compare the narration of the fall of 

 man, in Genesis, with the Persian saga of Ahriman and Or- 

 muzd) ; by others, such as the Egyptians and Phoenicians, it 

 was looked upon as a good genius (dyatfoSai'/zcoi/), and wor- 

 shipped as the emblem of fertility ; while by the Greeks and 

 Romans, whose mythology originated undoubtedly from 

 Egypt and the East, it appeared under a variety of symbolic 

 representations. With the latter, the serpent was the well- 

 known emblem of the healing art ; and in the present time a 

 serpent with its tail in its mouth is regarded as an emblem 

 of eternity. The serpent appears also to have held a place 

 in the Scandinavian mythology, where it was regarded as a 

 symbol of the human passions. In the early ages of the 

 Christian Church, a sect of the Gnostics also worshipped the 

 serpent, whence they were called Ophites (from ofas, a ser- 

 pent). See Mosheim's Geschichte der Schlangenbruder der 

 ersten Kirche. 



CHEMICAL AND MEDICAL PROPERTIES AND USES. 



Ail medicines possessing sufficient activity to be of much 

 value, are always poisonous in inordinate or excessive quan- 

 tities ; and every thing poisonous is capable of proving me- 

 dicinal in suitably reduced quantities. The ancient Greeks 

 employed the same word both for a medicine and a poison. 

 There are as many different modes in which poisons operate, 

 as there are different and distinct medicinal powers of any 



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