of Heat by Gaseous and Liquid Matter. 99 



zero, the gas was again permitted to enter the first chamber 

 exactly as in the first experiment, — the only difference between 

 the two experiments being, that in the first the heat passed 

 through a vacuum to the pile, while in the second it had to pass 

 through a column of the same kind of gas as that from which it 

 emanated. In this way the absorption exerted by any gas upon 

 heat radiated from the same gas, or from any other gas, may 

 be accurately determined. Finally, the apparatus being cleansed 

 and the needle at zero, the gas was permitted to enter the second 

 chamber, and its dynamic radiation from this chamber was deter- 

 mined. The intermediate plate of salt S' was shifted, as in the 

 former experiments, so as to alter the lengths of the two cham- 

 bers, but the sum of both lengths remained constant as before. 



In the following Tables the three columns bracketed under 

 the head of "Deflection," contain the arcs through which the 

 needle moved in the three cases mentioned; (1) when the radia- 

 tion from the gas in the first chamber passed through the empty 

 second chamber; (2) when the radiation from the first chamber 

 passed through the occupied second chamber ; and (3) when the 

 radiation proceeded from the second chamber. 



Dynamic Radiation of Gases. 

 Table XXXIV.— Carbonic Oxide. 





Length. 



Deflection. 







By 1st By 1st 



chamber, chamber, 

 2nd chamber gas in 2nd 

 empty. chamber. 



i 



1st 

 chamber 



2nd 

 chamber. 



By 2nd 

 chamber. 



2-8 

 15-4 

 36-3 



46-6 

 34-0 

 13-1 



o o 



1-0 o-o 



3-8 2'1 

 13-7 6-3 



28-0 

 24-4 

 16-6 





Table XXXV.— Carbonic Acid. 





2-8 

 15-4 

 36-3 



46-6 

 34-0 

 13-1 



1-0 00 

 3-7 1-25 

 16-8 6-6 



33-6 

 233 

 17-5 





Table XXXVI. —Nitrous Oxide. 





2*8 

 15-4 

 36-3 



46-6 

 34-0 

 13-1 



10 0-2 



4-3 1-2 



19-5 62 



44-5 

 3D7 

 220 





Table XXXVII.— defiant Gas. 





15-4 

 23-8 

 36-3 



34-0 

 256 

 13-1 



11-9 1-0 

 228 3-0 • 

 590 10-4 



H2 



68-0 

 65-0 



