On the Power of Fluids to conduct Heat. 379 
second cause abovementioned, and it would follow 
that warm water being put upon cold water above 
the temperature of 42°, the heat could not in 
any degree be propagated downwards, unless. by 
agitation, and even then, upon subsiding, the 
warm part ought to rise to the top, and the cold 
fall to the bottom. 
These positions are so manifestly contradic- 
tory to common-opinion, that they can not be 
received without proof. But Count Rumford has 
not given us a single experiment to prove them. 
It seemed necessary therefore, to clear up this 
point by direct experiments. 
2 
Experiment 1. 
Took a large tumbler glass, 9: inches di- 
ameter, and 5 inches deep, and filled it half way 
with water of 54°, then gently filled up the rest 
by means of a small syphon, with water of 88°; 
a thermometer, with its bulb.and stem detached 
from the frame, being previously immersed, to 
the bottom. ‘The temperatures at the top~ and 
middle were had by gently immersing the bulb 
of another thermometer into the water. 
