AND LIQUIDS AND THEIR VARIATION WITH TEMPERATURE. 



125 



30 a 40 50 60 70 



o. 



On account of the rapid way in which the methyl alcohol evaporated, it was 

 necessary to work quickly, and the numbers given for it are not quite as reliable as 

 those given for the other liquids. 



The last column contains the values obtained by H. F. WEBER,* for the mean 

 thermal conductivities between 9 and 15. 



As a result of the experiments, we may state that the thermal conductivities of 

 liquids decrease with increase of temperature in the neighbourhood of 30 C., at a 

 percentage rate which appears to be roughly the same for a number of liquids. 



PART III. CHANGE OF CONDUCTIVITY ON MELTING. 



Combining the last result with the one obtained for solids, Part I., and with the fact 

 that solids in general conduct heat better than liquids, and liquids better than gases, 

 we are led to conjecture that a given substance will, as its temperature is increased, 

 decrease in conductivity, and that the decrease will continue during any change of 

 state which the substance may undergo, owing to the increase in temperature. The 



VOL. CXCI. A. 



* H. F. WEBER, ' Berliner Ber.,' 1885, p. 809. 

 3 I 



