Cuar. IV.) THE EFFECTS OF HEAT. 63 
out Great Britain, and exists (Hooker) within the Arctic 
Circle, should be able to withstand for even a short time 
immersion in water heated to a temperature of 145°.* 
It may be worth adding that immersion in cold water does 
not cause any inflection: I suddenly placed four leaves, 
taken from plants which had been kept for several days at a 
high temperature, generally about 75° Fahr. (23°°8 Cent.), 
in water at 45° (7°-2 Cent.), but they were hardly at all 
affected; not so much as some other leaves from the same 
plants, which were at the same time immersed in water at 
75°; for these became in a slight degree inflected. 
* It appears the cold-blooded Burdon Sanderson, a frog begins to be 
animals are, as might have been distressed in water at a temperature 
expected, far more sensitive to an  ofonly 85° Fahr. At 95° the muscles 
increase of temperature than is become rigid, and the animal dies in a 
Drosera. Thus, as I hear from Dr. stiffened condition. 
