KNOBLAUCH OX RADIANT HEAT. 405 



the calcareous spar, in the first case to 16°'75, in the second 

 to 10°-5. 



The repetition of the same experiment with the rays of 

 red-hot platinum yielded the results detailed in the following 

 table :— 



Table XXXV. 



black paper, when transmitted through red glass and calcareous 

 spar, are less with the rays of red-hot platinum than with those 

 of the Argand lamp. The same applies to the differences which 

 occur in the other diathermanous bodies, and in consequence of 

 reflexion from all other surfaces. 



The reflexion of the heat of aflame of alcohol, when examined 

 in the same manner by means of transmission, led to the values 

 expressed in the subjoined table : — 



Table XXXVI. 



the insertion when the heat from the flume of alcohol is reflected by 



the red glass it receded to 5^-75, and to 4°-25 when the direct 

 deviation of 13^ was produced by reflexion from black paper; 



