1 8 J 
XXXII. 
ON SOME PROBLEMS CONNECTED WITH ATMOSPHERIC 
CARBONIC ANHYDRIDE, AND ON A NEW AND ACCU- 
RATE METHOD FOR DETERMINING ITS AMOUNT 
SUITABLE FOR SCIENTIFIC EXPEDITIONS. By 
PROFESSOR E. A. LETTS, D.Sc., Pa.D., ann R. F. BLAKE, 
F.1.C., F.C.S., Queen’s College, Belfast. 
[COMMUNICATED BY DR. W. E. ADENEY, F.1.C., F.C.S.| 
[Read January 16; Received for Publication January 28; Published June 6, 
1901.] 
In a recent memoir on the subject of the “‘ Carbonic Anhydride 
of the Atmosphere,’? we have directed attention to several 
problems which require investigation, especially the causes of the 
variations in its amount. On this point we express ourselves as 
follows :— 
‘These variations, if actually small, are relatively large, and 
correspond with fluctuations of at least 10 per cent. of the total 
quantity, and according to some observers to a much higher pro- 
portion. 
“Thus the oscillations in the amount of atmospheric carbonic 
anhydride must be admitted, even by those who take the lowest 
estimate, to be comparable in extent with the variations which 
occur in atmospheric pressure, and they may have a significance 
quite as important as these latter. 
“But in attempting to unravel the separate effects of those 
natural agencies which influence the proportion of atmospheric 
carbonic anhydride, very great difficulty is experienced, and indeed 
the task appears to be almost impossible in some cases with the 
material at present available for discussion. 
‘‘ This is due in great measure to the fact that many of the natu- 
ral agencies are antagonistic in their effect, and that several of them 
1 These Proceedings (New Series), 9 [1900] Part 2, No. 15. 
