288 MESSRS. THORPE AND iMORTON ON THE 



fore, to undertake its analysis, in the liope of supplying 

 information respecting the nature and extent of the modi- 

 fications effected in the composition of sea- water by its 

 proximity to our coasts. Accordingly Captain Temple, of 

 the ^Bahama Bank/ light-ship, kindly collected for us a 

 quantity of the water in the immediate neighbourhood of his 

 vessel. The vessel is situated in lat. 54° 21' N., and long. 

 4° 11' W., seven miles W.N.W. of Ramsey, Isle of Man, 

 and is placed nearly equidistant from the shores of Eng- 

 land, Scotland, and Ireland. During the greater part of 

 the day a strong current setting in from the south, pro- 

 bably from the Atlantic, flows past the ship into the Nortli 

 Channel, and thence again into the ocean. The water, 

 therefore, taken for analysis, was originally that of the 

 deep ocean, which had traversed almost the entire length 

 of the Irish Channel, and had consequently been ex- 

 posed to all the influences due to the neighbouring sea- 

 board, and to the influx of the numerous rivers along the 

 coasts. 



The water was obtained in the early part of January 

 1870. The meteorological conditions at the time of collec- 

 tion, and for some time previously, were in no wise re- 

 markable. The analysis was commenced immediately on 

 receipt of the water. Its specific gravity, compared with 

 distilled water, free from air, and possessing the same 

 temperature, was found to be 



At 0° C 1-02721 



15° C 1-02484 



These numbers differ but slightly from that usually ac- 

 cepted as representing the mean specific gravity of the 

 water of the ocean. The water of the Atlantic, according 

 to Von Horner, possesses the specific gravity i '02875 at 

 0°; that of the English Channel at I5°*5 was found by 



