DECEMBER. 
343 
C. — The Coatacook is now frozen over^ and I suppose 
will not open again before spring. Do the fishes become 
torpid ? or how do they sustain the severity of the season, 
when the water is covered with thick ribbed ice ?" 
F. — I apprehend that fishes in general do not become tor- 
pid, and I do not know that any species does : the tempera- 
ture of the lower parts of the water probably does not differ in 
a very great degree, at the different seasons of the year. The 
very ice that is formed at the surface contributes to preserve 
the equality of its temperature, and we know that as long 
as it remains fluid, it cannot be lower than 32" of Fahren- 
heit, whatever that of the air may be. There is another 
question, however, which may be raised : fishes cannot sub- 
sist, any more than terrestrial animals, without an absorp- 
tion of oxygen ; when the connexion of the water with the 
external air is cut off by a solid crust of ice, will they not 
sooner or later arrive at a point, when the water will part 
with no more of its oxygen ? That this is not an imaginary 
difficulty is proved by the fact, that fishes in a bowl of water 
placed beneath an exhausted receiver, soon die, although the 
water still contains much oxygen, or it would no longer be 
water, but hydrogen gas : though perhaps it refuses to part 
with any more. I once saw in Newfoundland a case in 
point : a little brook had been enlarged in one part into an 
oval fish-pond, containing perhaps two hundred square feet, 
in which the water commonly lay about eighteen inches 
deep ; a few trout lived in this little pool, that usually con- 
tinued open in the middle, through which the brook ran ; 
but one severe winter it was quite frozen over, and the fishes 
in the ensuing spring were found to be all dead. In the 
case of this river, however, the edges always communicate 
with the air, the ice breaking by friction, so that a stick may 
often be thrust down between the bank and the ice ; and 
were it otherwise, it would seem that the vast supply of 
