340 EXPERIMENTAL INVESTIGATIONS. 



ducting power of the wire, as measured by the amount of gas 

 in a voltameter included in the circuit : 



Cubic inches of gas evolved in 

 Gases surrounding the wire. the voltameter per minute. 



Hydrogen . . . . . 77 



Olefiant gas .... 7*0 



Carbonic oxide .... 6*6 



Carbonic acid .... 6*6 



Oxygen ..... 6*5 



Nitrogen ..... 6*4 



Assuming that in the present experiments the heat in the 

 water is a correct indication of the intensity of ignition in the 

 wire, the order is the same in both series of experiments. 

 Hydrogen is, however, so far removed from both oxygen and 

 nitrogen in its effects upon the ignited wire, that in order more 

 accurately to ascertain the relative position of the latter two 

 gases, I made a few farther experiments on them as contrasted 

 with each other, and not with hydrogen. I first repeated my 

 former experiment on these two gases, varying it only by 

 changing the circumstances in the manner suggested by the 

 present experiments, which, on account of the vessel contain- 

 ing the wire being immersed in a given quantity of water, 

 instead of being exposed to the external atmosphere, would 

 occasion greater equality in the surrounding cooling effects, 

 and would give me the opportunity of combining both 

 methods in one experiment. 



I filled both tubes A and B with oxygen, and included a 

 voltameter in the circuit ; in two minutes 3-43 cubic inches of 

 hydrogen were evolved in the voltameter, and the thermo- 

 meter in each cell had risen from 60 to 63. A similar ex- 

 periment with nitrogen gave in two minutes 3*4 cubic inches 

 of hydrogen, and the thermometer rose from 60 to 63. 



This experiment accords with my previous one as to the 

 voltameter test, but indicates no difference in oxygen and 

 nitrogen with the thermometer test ; I therefore in the follow- 

 ing three experiments associated nitrogen with oxygen in the 

 apparatus (fig. i). All things being disposed as with the ex- 

 periments on hydrogen associated with other gases, in five 

 minutes the thermometer rose 



