150 MR. T. E. THORPE ON THE AMOUNT OF CARBONIC ACID 



VIII. On the Amount of Carbonic Acid contained in the Air 

 above the Irish Sea. By T. E. Thorpe^ Assistant in the 

 Private Laboratory, Owens College. Communicated by 

 Professor H. E. Roscoe, F.R.S., &c. 



Read NoTember 28th, 1865. 



The determination of the amount of carbonic acid con- 

 tained in the atmosphere over the land has been made the 

 subject of investigation by many experimenters; and from 

 the results obtained by Theodore de Saussure, Brunner, 

 Boussingaultj Angus Smith, and others, we are acquainted 

 with the exact proportion of this gas contained in the at- 

 mosphere under varying circumstances of situation and 

 weather. 



But hitherto the influence which, a priori, must neces- 

 sarily be exercised by large bodies of water on the propor- 

 tion of carbonic acid in the atmosphere has scarcely been 

 sufficiently studied. The fact that a considerable influence 

 is exercised has certainly been noticed; but beyond the 

 incomplete results of one or two observers, we have no 

 numerical data from which to judge of the extent of this 

 influence, and we therefore, know but little of the changes 

 in the comparative amount of the atmospheric carbonic 

 acid as efi"ected by the waters of the ocean. Dr. Hoscoe 

 therefore suggested that I should undertake some experi- 

 ments on this subject, and kindly placed the necessary 

 time and apparatus at my disposal. I may here be allowed 

 to express my thanks for the kindness and for the advice 

 and assistance I have received from him during the prose- 

 cution of these experiments. 



It was noticed long ago by Vogel (Ann. of Phil. vi. 

 1823, and Journ. de Pharm. t. vii. p. 461) that air col- 



