1C8 A NATURAL HISTORY 



Bodies. The Serpentine Line, smong Mathematicians, is bor- 

 rowed from the Foldings of a Serpent in its Motion. 



The Learned obferve, there is a great deal of geometrical 

 Nicenefs in the finuous Motion of Snakes, Vipers, and other Ser- 

 pents; to affift them in the right Management of it, the annular 

 Scales under their Bodies are very remarkable, lying crofs tlie Belly, 

 contrary to what thofe in the Back, and the reft of the Syftem do ; 

 which Contrivance facilitates their Motion. 



This tortuous creeping Motion of the Reptile Species is very 

 curious : The whole Body of a Worm is, as it were, but a Chain 

 of annular or fpiral Mufcles, whofe round Fibres, by contrad:ing, 

 make each Ring more ftrong. The Back-Bones of Serpents are 

 a wonderful Compofition : How thick are they with Joints ? How 

 numerous and ftrong are their co-operating Mufcles ? By this cu- 

 rious Articulation of the Joints, they can turn and wind their Bo- 

 dies any way without any difficulty. 



The Outfide of their Skin is a moft elegant Compofition : to a 

 common Eye, their Tegument has a rugged uneven Afpe6l; but, 

 to a proper Judge, the Scales of Vipers are found to be a moft ex- 

 quifite Piece of Mechanifm ; the Symmetry of the whole is geo- 

 metrically exait, and vaftly beautiful ; not imitable by human Skill : 

 Some of them are guarded by a coverture not penetrable by a 

 human Arm, which is their Security in a perilous Situation ; yea, 

 a greater Security than many innocent Lihabitants of the Field 

 are privileged with. Among Serpents, fome are clothed as with 

 a Coat of Mail, /. e. an Armature of ftrong Scales j and fuch of 

 them as want that cruftaceous Covering, have either a Sting in the 

 Tail, or a Tooth in their Mouth, that bids the AfTailant keep off, 

 and obferve his Diftance. 



S E T I O N VII. 



^HAT is Foifon ? I anfwer, that, generally fpeaking, 'tis 

 taken to be a malignant Quality in fome Vegetables, 

 Minerals, and Animals , a fmall Quantity of which is hurtful, 

 and even mortal, ^t, 



T H- K 



