B. TERRESTRIAL PHYSICS AND METEOROLOGY. 59 



justifies no conclusion as to the amount in the water. The 

 portions of the sea-water gas first displaced are almost en- 

 tirely free from carbonic acid, the later being richer. 



The complete expulsion of carbonic acid from sea-water is 

 attained by its distillation in a current of air free from car- 

 bonic acid ; but even under this operation it is detached so 

 slowly that only after the evaporation of a considerable 

 amount of water does the carbonate of lime begin to sepa- 

 rate. The distillation must be continued until only one 

 fourth of the original quantity of water remains. The fact, 

 therefore, that carbonic acid is present in sea-water, not as 

 a dissolved gas in the same sense as oxygen and hydrogen, 

 but in a peculiar condition of combination, Mr. Jacobsen con- 

 siders of great importance, not only as respects animal and 

 vegetable life, but also in reference to the geological rela- 

 tions of the sea. He is now prosecuting an inquiry as to 

 which of the constituents of sea-water is due its power of 

 close combination with carbonic acid, and what is the pro- 

 portion of this acid to the salt. 12 A, August 8, 1872, 279. 



CARBONIC ACID OP SEA-WATER. 



Mr. Lant Carpenter, who has been investigating the amount 

 of gaseous constituents in samples of deep sea-water obtained 

 during the Porcupine expedition of 1869-70, remarks that 

 the analyses show that both surface and bottom water con- 

 tain more carbonic acid and less oxygen in the more southern 

 than in the more northern latitudes. The examinations made 

 embraced samples taken from localities extending from the 

 Faroe Islands to Lisbon. Contrary to the general supposi- 

 tion, however, he reports that there is no greater quantity of 

 dissolved gaseous constituents in the bottom than in the sur- 

 face water, although he fully admits the power of pressure 

 at great depths to retain gases in solution if once evolved 

 there. 1 A, August 23, 1872, 88. 



DISCUSSION OF DEEP-SEA TEMPERATURES. 



Professor Mohn, of Christiania, discussing in Petermann's 

 Mittheilungen the results of the deep-sea temperature obser- 

 vations in the waters between Greenland, North Europe, and 

 Spitsbergen, remarks that the deep basin of the polar sea is 

 filled from bottom to top with an enormous mass of cold 



