414 SIR RODERICK I. MURCHISON'S ADDRESS. [May 25, 1857. 



our next Volume. Unluckily the quantities of the water sent home 

 were far too small to admit of rigid chemical analysis. Thus, in 

 regard to the discolouring matter, it could only be ascertained, that 

 it was a suspended, light, yellowish, flocculent substance, which 

 affected the usual green colour of the sea, and is in all probability 

 of organic (vegetable?) origin. The specific gravity, however, of 

 the water has been determined, and the result, as will be shown in 

 a table, confirms the observations of Mulder and Dr. John Davy, of 

 a diminution of such gravity in sea-water as it approaches the 

 mouths of rivers. Mr. Witt further mentions the results of other 

 observers, and states, that after a series of experiments, in a voyage 

 from Southampton to Bombay, MM. Adolf and Hermann Schla- 

 gintweit give 1*0277 as the mean specific gravity of the Atlantic; 

 whilst our late member, Admiral Philip King, found the mean 

 specific gravity of the Pacific to be 1*02648 between 10° and 40° 

 s. lat., and 1*02613 between 40° and 60° s. lat. It would, therefore, 

 appear probable, that whilst the density of inland seas, such as the 

 Mediterranean, is higher than that of the broad oceans, the Atlantic 

 will be found to have a higher specific gravity than the Pacific — a 

 point, however, which ought to be ascertained accurately by nume- 

 rous determinations of the quantity of saline matter in the waters of 

 each of these oceans.— (^ee Smyth's ' Mediterranean,' p. 131.) 



Permanent Effects of Winds and Currents. — By perseveringly ob- 

 serving the phenomena attendant upon the wear and tear of the 

 coast of Caithness, and by pondering upon the changes that have 

 taken place in and about the harbour of Wick, Mr. John Cleghorn, 

 of that town, after pointing out that the south-west side of the har- 

 bour was comparatively shallow and its north-east deep, extended 

 this observation, and found it to be true as respected other bays of 

 the east coast of Scotland. The same observer, who had previously 

 roused attention to the ruinous effects of the present system of 

 fishing, in destroying the breed of herrings, and who has also 

 written an able notice upon the formation of rock basins by 

 the action of waves upon large stones (both derived from his own 

 examination), was, in this case, led to believe that the natural 

 cause affecting Wick harbour has been the long- continued preva- 

 lence of the south-west wind, which produced waves that had 

 worn away the north-eastern headlands into precipices, and had 

 sent back the debris by a counter or reflux current, which neces- 

 sarily tended to shoal up the opposite or south-western side of the 

 bay. 



