Natural History of the Ocean, 8fc. 129 



dance of red fish. Near Sumatra and on the coast of Chili, 

 the water seems red from a minute vegetable substance 

 that floats in it. 



Temperature. —M the Equator, the surface water is 80°; 

 Farenh. ; at 28 N. Lat. it is 68° ; at 47 N. Lat. it is 58*5 

 in the arctic regions it is about 30° ; diminishing as the 

 latitude increases. 



The temperature, at a considerable depth, is higher on 

 approaching a coast ; but at a distance from land it dimin- 

 ishes as the depth increases. When the atmosphere is 50° ; 

 and the surface water 40° ; it will be perhaps only 25° at 

 the depth of 50 fathoms. The reverse of this was supposed 

 to be true in lakes, but the late experiments of M. de la 

 Beche, prove the Swiss Lakes to agree in this particular 

 with the variations of ocean temperature. 



The diminution of temperature on the banks of New- 

 foundland is so great, that the thermometer may justly be 

 considered as an indicator of the approach to land on the 

 east coast of the U- States. 



The Gulf Stream is about 15" warmer than the surround^ 

 ing bed of the ocean. Summary — 



1. The temperature of the ocean diminishes from the 

 Equator to the Polar regions. 



2. It decreases near Islands and Continents. 



3. It diminishes in wide seas, according to the depth 

 from which it is drawn : except in the polar seas, where 

 the reverse obtains. 



4. It is less on sand banks. 



Remarks.-^\t is owing to the extreme mildness and equa* 

 bility of temperature enjoyed by the ocean and superna- 

 tant atmosphere, that the good effects are derived from sea 

 air in pulmonary complaints : and not from the saline hu- 

 midity of the air, as has been asserted. Thiscircumstanct 

 has not been sufficiently insisted upon by medical men. 

 We may learn from it the utility of sending patients on a 

 voyage into the wide ocean, where the air is not aflfected 

 by the various changes on land; we may also see the imi^ 

 tihty of coasting voyages for consumptive persons. 



Specific Gravity. — The experiments of the celebrated 

 Capt. Scoresby, Dr. Marcet, and Dr. Traill sanction the 

 following inferences. 



1. The sp. gr. of the waters of the Atlantic decreases 

 from the Equator to the poles : being at the Equator 1.0^5 \ 



Vol, V.--No. I. 17 



