104 ON THE POISON 



one another, that it is impoffible, without great ex- 

 perience, to dillinguifh them. The fkin on the belly 

 and tail of ferpents, is compofed of fcales, which vary, 

 in number and arrangement, in different ferpents. 

 Upon this circumftance, Linn^us has founded his 

 divifion of the ferpent tribe into fix diftin£t genera. 

 JJut this divifion, however ufeful it may be to the 

 naturalift, is of little ufe to the phyfician, who is de- 

 firous of diftinguifliing the harmlefs from the venomous 

 ferpent: the colour, which is moft commonly attended 

 to, is a very fallacious mark, for it commonly changes 

 with age : a fcr};ent with a large head, is generally 

 fufpected to be venomous; but the mark which is 

 chiefly to be depended on, is the large canine teeth, 

 or fangs, fixed in the upper jaw, which are commonly 

 two in number, but fomctiniCS more. Thefe teeth are 

 covered with a membranous Iheath, and are crooked, 

 moveable, and hollow, to give pafTage to the venom, 

 which they receive from a fmall refervoir, that runs 

 along the palate of the mouth, and palTcs through the 

 body of each fang. This refervoir contains but a very 

 fmall quantity of venom, which is forced out ofit when 

 tlie animal attempts to bite, by a frrong mufcle fixed 

 to the upper jaw, and that covers it nearly through 

 the whole of its length. This is the means of defence 

 given to ferpents; it has been well obfervcd by 

 hiiJKMus, that if nature has thrown them naked on 

 the ground, deftitute of limbs, and expofed to every 

 injury, fhe has in return, fupplicd them with a deadly 

 ])oifon, the moft terrible of all weapons, and which has 

 made them, from the earlieft ages, to be regarded as 

 objects of horror, or of religious veneration, by the 

 liuman race. 



SECTION II. 



The fymptoms which arife from the bite of a fer- 

 pent, are commonly pain, fwelling and rednefs in the 

 part bitten; great faintnefs, with licknefs at ftomach, and 

 fometimcs vomiting, fucceed ; the breathing becomes 



fliort 



