392 On the Power of Fluids to conduct Heat. 
facts, however, will. admit of a satisfactory ex- 
planation upon established principles. . 
By experiments 10 and 13, it appears, that 
the quantity of heat given out by a body, 
during any small given portion of time, is nearly 
as the excess of the temperature of the body 
above the cooling medium. Hence, then, we 
may conclude, that the effect of hot water upon 
ice arising from the proper conducting power of 
water, will be nearly as the heat of the water. 
What effect the other cause may produce, it will 
be difficult to determine from theory: Experience 
will be the best guide, One thing, however, 
appears pretty certain, that its effect must be 
a maximum, when the temperature of the water at 
large is 42°; because then there can never want 
a determination of the particles downward to 
supply the place of the lighter water of 32° as. 
cending. If the temperature ofthe water exceed 
42°3, then the effect of the internal motion will 
be less, diminishing by some unknown ratio. As 
far as I can judge from Count R.’s experiments, 
the joint effects of those two causes should be 
nearly the same with water of 42° and water of 
190°. Taking this, therefore, for granted, we 
shall be enabled to sketch a table of the values 
_ of these two causes for every 10° of temperature, 
The numbéts expressing the effect of the proper 
conducting power, are derived from the 1oth 
