510 WITT'S REPORT ON SEA-WATER. [June 22, 1857. 



SO that it would appesTr probable that the Atlantic has a higher 

 specific gravity than the Pacific, and it would be interesting to con- 

 firm this by further observations, or more correctly by actual deter- 

 minations of the quantity of saline matter. 



Of course the density of inland seas, as the Mediterranean, &c., is 

 higher than that of the Atlantic or Pacific Oceans. 



Although the fact of the diminution of the specific gravity of sea- 

 water by the influx of large rivers is an observation which we should 

 anticipate a priori^ I find only two other recorded sets of experiments 

 on the point. Mulder * states that the specific gravity of the At- 

 lantic falls, in the North Sea, where several large rivers enter 

 it, to 1-0255 ; and Dr. John Davy j found that at the mouth of the 

 Demerara the density of the water was 1-0036, w^hilst that of the sea 

 eighty miles distant was 1*0266; and my own experiments show a 

 similar diminution, the sample taken nearest the Loando coast (viz. 

 in long. 8° 27' E.) having a specific gravity of 1*02520, whilst in 

 the long. 3° 37' E., or 4° 50' further from the coast, the specific 

 gravity of the sea-water rose to 1-02786. 

 I have, &c., 



Heney M. AVitt, F.C.S., Assistant Chemist. 



To Sir Roderick Impey Murch'son, president r.g.s., &c., &c. 



The President next announced the titles of other papers which, for want 

 of time, had not yet been read. 



He had also to call their attention to a series of remarkable water-colour 

 sketches of the mountains of porphyry, basalt, and other igneous rocks in 

 the interior of Asia, extending into China— countries of which they had 

 hitherto possessed little knowledge. The explorer of this region, Mr. Atkinson, 

 was present, and was about to produce a beautifully illustrated work which 

 would throw new light upon the structure of the interior of Asia. 



The President then gave some information respecting the expedition which 

 was about to proceed to the Arctic regions under Captain M'Clintock, Great 

 importance was attached to the acquisition of an interpreter, and they knew 

 that an Esquimaux interpreter was not easily obtained. The Secretary had 

 long ago been in correspondence with Captain Irminger, of the Danish navy, to 

 procure the services of that excellent man Petersen, who had lived among the 

 Esquimaux in Greenland a long time, and who had already served as inter- 

 preter with Penny and Kane. That person had arrived from Greenland at 

 Copenhagen a few days ago, and intelligence of the fact having been received 

 on Saturday, he (the President) had immediately telegraphed to Captain Irminger, 

 requesting him to send off Petersen at once. He was happy to say that an 

 answer had been received, stating that Petersen would be in I^ondon on 

 Wednesday, and proceed on Thursday to Aberdeen. The expedition would 

 sail immediately on his arrival. 



In concluding the business of the meeting, and at the same time closing the 

 session of 1856-57, the President said he was sure his associates would admit 



* Poggeudorf s Annalen, xxxix. 513. 



t Edinburgh New Philosophical Journal, xliv. 43. » 



