AZOTIC GAS. 



umes of deutoxide of azote ; the gaseous mix- 

 ture assumes an orange colour, and diminishes 

 rapidly in volume. When the gas has become 

 again colourless, and has ceased to diminish, its 

 bulk will be found to amount to 138 volumes. 



To be able to understand what really takes 

 place in this experiment, we must recollect that 

 common air consists of 20 volumes oxygen gas, 

 and 80 volumes azotic gas ; and that the yellow 

 colour is occasioned by the combination of the 

 oxygen of the common air, with the deutoxide of 

 azote and the formation of nitrous acid. The 

 whole oxygen of the air disappears, and the 

 amount of the residual gas will enable us to judge 

 of the volume of deutoxide, with which it com- 

 bines. 



The experiments were made over water at the 

 temperature of 60. Had the air and deutoxide 

 been dry, instead of saturated with moisture, each 

 would have occupied only 98*253 volumes instead 

 of 100 ; so that the whole gaseous matter used, 

 had it been dry, would have occupied 196*506 

 volumes. The 138 volumes of residual gas, sup- 

 posing them dry, would be reduced to 135*589 

 volumes. This last quantity subtracted from 

 196*506 (the original volume) leaves 60*91? vol- 

 umes for the quantity absorbed or converted into 

 nitrous acid. 



Now 98*253 volumes of common air, contain 

 19*65 volumes of oxygen, which, in order to be 



