386 Onthe Power of Fluids to conduct Heat. 
by an alteration of specific gravity ; but not 
solely to that cause as Count Rumford has in- 
ferred. 
If it be proved that water conducts heat, it 
will scarcely be necessary to prove, that other 
fluids conduct it, and that they communicate it 
one to another :—The two following experiments 
shew that mercury conducts it, and that water 
and mercury reciprocally communicate it. 
Experiment 7. 
Took a cylindrical glass tube, of 1 inch in- 
ternal diameter, and put 13 inches in depth of 
mercury into it, and immersed the bulb and 
stem of a thermometer to the bottom, the scale 
as usual being above the liquid; then put 24 
inches of warm water upon it by a syphon, and 
let it stand without agitation, 
TEMPERATURE. TEMPERATURE. 
Merc. Waiter. Time. Merc. Water, 
Time. 56° 122 14M, 74°F 92° 
3m. 70 118 19 73 87 
6 73 110 27 71 78 
11 75 190 
Experiment 8. 
Into a tumbler glass, 2} inches in diameter, — 
poured an inch in depth of mercury, and heated 
