On thé Power of Fluids to conduct Heat. 391 
Time. Temp. Time. Temp. 
16 56°.3 24 55°33 
17 563 25 55-25 
18. 56 26 55-2— 
19 55-9 27 55-1 
20 557+ | 28 551— 
21 55-6+ 29 55+ 
22 55:5 39 55 
23 55-4 
In these experiments we may consider mer- 
cury and air mixed together of unequal tem- 
peratures, with a thin partition of glass—and 
from the last we may conclude, that the thermo 
meter imparted to the air 40 times more heat in 
half a minute, when its temperature was 30° 
above the air, than when it was only 1° 
above it. 
We shall now advert a littleto CountRumford’s 
experiments.—It will easily appear, that arguing 
fairly upon his own hypothesis he can never ac- 
count for the phenomena observed: For, hot 
water being poured upon ice, an internal motion 
would take place near the surface of the ice, by 
which a stratum of water of a certain thickness 
would be reduced to ge2°, and then all further 
reduction of the ice must cease; because all the 
superincumbent water being above 53° would be 
lighter and could not descend to, the ice. But’ - 
this is quite contrary to what took, place. .The 
VOL, Y. K 
