102 Prof. Tyndall on the Absorption and Radiation 



above recorded. Indeed I do not doubt my ability to cause the 

 needle of my galvanometer to whirl, by the dynamic heating of 

 the surface of my pile, through an arc of 1000 degrees. As- 

 suredly an arrangement subject to disturbances of this character 

 cannot be suitable in experiments in which the greatest delicacy 

 is necessary. 



Experiments on dynamic radiation, similar to those executed 

 with gases, were made with vapours. The tube was divided 

 into two compartments as before. Both compartments being 

 exhausted, vapour was permitted to enter the first chamber. 

 Dry air was afterwards permitted to enter the same chamber ; 

 the air was heated, it warmed the vapour, and the vapour 

 radiated its heat against the pile. The heat passed in the first 

 experiment through a vacuous second chamber, and in the 

 second experiment through the same chamber when it contained 

 0*5 of an inch of the same vapour as that from which the rays 

 issued. A third experiment was made to determine the dynamic 

 radiation from the second chamber. The following Tables con- 

 tain the results : — 



Dynamic Radiation of Vapours. 

 Table XXXVIII.— Bisulphide of Carbon, 0*5 inch. 



Length. 



A 



Deflection. 



A 





1 



1st 



chamber. 



2nd 

 chamber. 



By 1st By 1st 

 chamber, chamber. 

 2nd chamber Vapour in 

 empty. 2nd chamber. 



By 2nd 

 chamber. 



15-4 

 36-3 



34-0 

 13-1 



o o 



2-4 1-6 

 975 5-5 



14-2 

 90 





Table XXXIX.— Benzole, 0-5 inch. 





15-4 

 36-3 



34-0 

 13-1 



30 1-1 

 21-6 11-9 



34-0 

 15*1 





Table XL.- 



—Iodide of Etbyle, 0'5 inch 





15-4 

 36-3 



340 

 131 



3-4 2-7 

 25-4 13-8 



38-8 

 19-0 





Table XLI. — Chloroform, 0*5 inch. 





15-4 

 36-3 



34*0 

 13-1 



4-5 2-1 

 223 10-0 



41-0 

 19-0 





Table XLII.— Alcohol, 0'5 inch. 





15-4 

 363 



34-0 

 131 



4-9 2-0 

 338 16-9 



53-8 

 34-9 



