Lerts & Brake—The Carbonic Anhydride of the Atmosphere. 2138 
The present explanation is still incomplete as it does not dispose of 
the carbonic anhydride which was on the mountain when the cloud 
arose, or when the moisture was condensed into cloud on the spot. 
Two other observers have touched on the effects of altitude, 
namely, N. V. Lorenz, who found on the Sonnblick (3100 m.), on 
August 27 and 28, 1887, 2:05 and 2°36, respectively, which are 
certainly very low figures; and Andrée who collected air from 
balloons in 1894, and found that its content of carbonic anhy- 
dride at altitudes of 1000-3000 m. (3°23) was practically the same 
as at the surface (3:03-3:20). It would, therefore, appear that 
whereas the earlier observers found that attitude had a distinct 
influence on the amount of atmospheric carbonic anhydride— 
according to some, lowering it, and according to others, increasing 
it—their successors have been unable to detect any very distinct 
effect one way or the other. 
The experimental evidence is, however, scarcely sufficient to 
warrant any very definite conclusions, and further observations 
would be of interest especially from balloons in calm weather. 
For reasons mentioned elsewhere, atmospheric carbonic anhy- 
dride——at least over land surfaces—should decrease with altitude, 
and some observers have drawn attention to the fact that the 
determinations made by the later and more reliable methods 
favour this view. 
(As regards the amount of atmospheric carbonic anhydride at 
ground level, and at moderate heights above it, see p. 216.) 
