KNOBLAUCH ON RADIANT HEAT. 



197 



to the same extent whatever the degree of heat of the radiating 

 body was, w ithin the limits to which this investigation extended. 

 In this experiment it was a matter of indifference whether the 

 radiating surface of the Leslie's cube consisted of metal or glass, 

 or whether it was coated with lamp-black, wool, or other sub- 

 stances. The same was found to be the case with all other 

 diathermanous bodies. Thus the needle receded each time to 

 18^ when, with a constant direct deflection of 35°, white mica 

 0*2 millim. in thickness was inserted betvi'een the Leslie's cube 

 and the thermoscope ; and each time to 20°, when this was ex- 

 changed for green mica O'l millim. in thickness. The following 

 table will exhibit this still more distinctly. 

 Table II. 



