knoblauch on radiant heat. 413 



Table XLI. 



insertion when the heat of theftame of alcohol is reflected by 



copper. 



4-87 

 4-25 

 212 

 16 00 

 9-87 

 7-87 



surface and the instrument. The same uniformity was observed 

 in the thermoscopic indications with these surfaces, when the 

 other diathermanous bodies were used. How perfect it is in the 

 case of the other pairs of reflecting substances also, is evident 

 from the above table. 



It was not to be expected that any difl'erences would occur in 

 the present instances, when exposed to the influence of the iron 

 q/linder at a dark red heat, with which even the greatest differ- 

 ences perceived in other sources of heat vanish (see p. 403-409). 

 Observation has confirmed this : — 



Table XLII. 



insertion when the heat of the hot metallic cylinder is reflected by 



portment when exposed to the rays of the Argand lamp, also 

 reflected the rays of the other sources of heat in the same man- 

 ner ; for the rays of heat reflected by silver and sheet iron, white 

 ' and black silk, light and black cloth, white oil-paint and black 

 j lac, yellow leather and brown Spanish leather, white and red 

 wool, cinnabar and peroxide of copper, on transmission through 

 all those bodies which have as yet been used, are always found, 

 in the cases mentioned, to act the same. 



