J^r^s On the Tendencij of 



purity as at first ; for 3 parts of it required 4 

 of atmospheric air to saturate them. 



3. Nitrous gas and one ^ oxygenous were 

 tried in the same way : after four hours, the 

 apparatus was taken down under water. The 

 upper phial was ^ filled with water, and the 

 gas in it was partly driven down the tube into 

 the other phial, by which, and the previous 

 process, the nitrous gas was completely satu- 

 rated and nothing but azotic with a small 

 .portion of oxygenous were found in the under 

 phial : the remaining gas in the upper phial 

 was still t oxygenous, 



, 4. Jvjtvous gas and hydrogenous: in three 

 hours the upper phial was 4 nitrous, and of 

 course the under must have a like part of 

 hydrogen. 



5. Nitrous gas and azotic : after three hours 

 the upper phial was -J- nitrous. 



In the two last experiments, the quantity of 

 nitrous gas in the upper phial was less than 

 might be expected ; but the tube was at first 

 filled with common air, and some must enter 

 on connecting the apparatus, which is sufli- 

 cient to account for the results. 



