COMPOSITION OF THE ATMOSPHERE. 



13 



It is exceedingly probable that the difference of com- 

 position is somewhat connected with the existence of water 

 in the atmosphere j or it may be simply the result of 

 separation caused by the weight of the gases — a result^ cer- 

 tainly, which has been much discussed and is well known 

 not to exist in proportion to the weight, and one by no 

 means probable, considering the investigations of Graham : 

 but that the physical cause may after all be struggling so 

 as to make itself in some way felt, it is perhaps rather 

 daring for us to deny absolutely. If the oxygen were 

 diminished without the increase of the carbonic acid, it 

 would be safest to advocate the latter reason. The reasons 

 given in the previous paragraph agree best with the state 

 of our knowledge. However, the discussion on this subject 

 would be better postponed until we become absolutely sure 

 of more facts. 



Air of Impure Places. 



Reliable analyses of the air of impure places are less 

 numerous than those given ; but decided results have been 

 obtained, showing at least a deviation from the numbers 

 found on analyzing fresh air. 



Observer. 



Configliachi 

 Eegnaulfc . . . 



Air of rice-fields 

 Crowded places 

 Toulon harbour 

 Algiers 



Bengal Bay 



Do. OTer bad water 



I found in the middle of Manchester, in a place ^ 

 closely surrounded and exposed to smoke .... 



20-8 



20-3 



20*85 



20*42 



20-395 



20*46 



20*387 



20*868 



20*8o8 



20*807 



20*613 



20*793 



20*179 



20*652 



