425 



as a plea for a thorough investigation of the problem. In our 

 times, when the greater part of the ocean is traversed day by 

 day, throughout the year, by innumerable steamers, it ought to 

 be possible to undertake such an investigation, which must of 

 course be of an international character. 



In all regions of the ocean samples of surface-water and 

 also of atmospheric air must be collected at regular intervals 

 throughout a whole year, and the corresponding temperatures 

 and meteorological conditions observed. The manipulations are 

 so simple and easy to perform that this part of the work could 

 safely be intrusted to the hands of ships-officers. A number 

 of suitably situated laboratories , marine or chemical , must 

 further unite for the execution of the analyses , consisting 

 chiefly in the determination of the tensions of carbonic acid in 

 the water and in the air respectively. It is obvious that the 

 general usefulnes of such an undertaking would be greatly 

 enhanced, if the salinity and perhaps the alkalinity of the waters 

 were simultaneously determined. 



Before leaving this subject it will be necessary to add 

 some words concerning the influence of the climate on the 

 state of equilibrium and also the possible interaction between 

 the atmospheric carbonic acid and the climate. 



The influence of the temperature upon the tension-equili- 

 brium between the ocean and the atmosphere is in its general 

 features easily accounted for. The tension of carbonic acid in 

 the ocean will rise and fall along with the mean temperature 

 on the earth, and the percentage of the gas in the atmosphere 

 must thereby be influenced. A decrease in the mean tempe- 

 rature on the earth amounting to 3.2° would cause a decrease 

 in the tension of the ocean of about Vio of its value at the 

 time ^) or from 0.03 to 0.027. The decrease of the ocean-tension 



^) See the preceding paper pp. 363—65. 



