KNOBLAUCH ON RADIANT HEAT. 



195 



Radiation through gypsum exhibited similar phaenomena. 

 The heat of the hydrogen flame certainly passes through potash- 

 and magnesian mica less freely than that of the three other 

 sources ; an observation to which I wish especially to draw 

 attention, because it is opposed to the expectations which we 

 should make after the experiment instituted by Melloni with 

 mica. 



The following table contains the results which have been ob- 

 tained on the transmission of heat through the diathermanous 

 bodies above mentioned, as well as some others, for various 

 direct deflections. 



Table I. 



