Elastic Fluids to Difuslon. 267 



FOlUnil CI. ASS. 



AZOTIC 



xcith mixlures containing oxi/gaions gas. 



1 . Azotic gas and one -J- oxygenous : after 

 standing three hours the upper phial was of the 

 standard 1.78, or about ^-'^: oxygenous. 



'2. Azotic gas with atmospheric air: after 

 standing three hours : the upper phial was not 

 sensibly diminished by nitrous gas ; the under 

 phial, however, had lost 2 per cent, or -^ of its 

 oxygen. The reason of this was, that the 

 azotic gas in this experiment having been just 

 made for it from nitrous gas, this last had not 

 been completely saturated with atmospheric 

 airi dnd hence had seized upon all the oxygen 

 ascending into the upper phial. 



Having now related all the experiments I 

 rnade of any importance to the subject, it will 

 be proper to add, for the sake of those that 

 may wish to repeat some of them, that great 

 care must be taken to keep the inside of the 

 tube dry ; for if a drop of water interpose be- 

 tween the two gases, I have found that it 

 effectually prevents the intercourse : Glass 

 tubes should tlierefore be used, that one may 

 be satisfied on this head, as the obstruction 

 will then be visible, 



1 I 'i 



