of food it is supplied with; a single pike having 

 been known to devour a hundred roaches in three 

 days. Its faculties also are as extraordinary, for it 

 digests not only soft fish, but prawns, crabs and 

 lobsters, shells, and all. These the cod or the stur. 

 geon will not only devour, but dissolve, though their 

 shells are so much harder than the sides of the stomach 

 which contains them. This amazing faculty in the 

 cold stomach of fishes has justly excited the curiosity 

 of philosophers : and has effectually overturned the 

 system of those who suppose the heat of the 

 stomach is alone a sufficient instrument for diges- 

 tion. The truth seems to be, that there is a power 

 of animal assimulation lodged in the stomach of all 

 creatures, which we can neither describe nor define, 

 converting the substances they swallow into a fluid, 

 fitted for their own peculiar support. This is done 

 neither by trituration, nor by warmth, nor by motion, 

 nor by a dissolving fluid; but by some principle yet 

 unknown, which acts in a different manner from all 

 kinds of artificial maceration. 



Yet though fish are thus hungry, and for ever 

 prowling, no animal can suffer the want of food for 

 so long a time. The gold and silver fish which we 

 keep in vases, seem never to want any nourish- 

 ment at all ; whether it be that they feed on the 

 water-insects, too minute lor ur observation, or 

 that water alone is a sufficient supply. Even the 

 pike, the most voracious of fishes, will live in a 

 pond where there is none but himself, and what 

 is more extraordinary, will be often found to thrive 

 there. 



Air however is so necessary to all fish, that they 

 can live but a tew minutes without it : yet nothing is 

 more difficult to be accounted for, than the manner 

 in which thay obtain this necessary supply. Those 

 who have seen a fish in the water, must remember 

 the motion of its lips and its gills, or at least of the 

 bones on each side that cover them. This motion in 



