THE ATLANTIC OCEAN. 203 



of the Northern Atlantic through which they flow. But as 

 the difference scarcely exists half a per cent., we hesitate in 

 believing, with Captain Maury, that this greater saltness is 

 the sole source of the deep blue colour they assume. We 

 receive, too, with distrust his speculations on what he con- 

 siders the probable 'galvanic qualities ' of this great stream. 

 We have little doubt, indeed, that the electrical element, 

 pervading in one or other of its forms the whole material 

 world giving motion and change to masses as well as 

 molecules, and evolved or altered itself by every such motion 

 and change may have some concern, as cause or effect, in 

 the natural phenomenon before us. But we perceive at the 

 present time so much tendency to make use of this great 

 power as the basis of vague and fruitless speculation, that we 

 are always suspicious in the outset, when we find its agency 

 invoked to solve a physical problem. In the present case 

 we see no especial reason for having recourse to it. The 

 physical conditions of the Grulf-stream its definite direction, 

 its force, its temperature, its saltness, its relation to Atlantic 

 winds and storms, and its tardy intermingling with the 

 mass of ocean may be referred, with more or less proba- 

 bility, to other natural causes in certain and constant 

 operation. We cannot exclude electricity from the number, 

 but we must not invoke it on the slender evidence which our 

 author places before us. 



These considerations lead us to the theory of the Gulf- 

 stream; a matter on which a good deal has been written; 

 and speculations put forward on very insunicient proof. Such 

 is, the early opinion that it owes its origin to the river waters 

 of the Mississippi, forcing a sea current before them out of 

 the Grulf-basin an opinion at once refuted by the utter 

 disproportion between the alleged cause and the observed 

 effect. It would, in fact, be the case of 300 volumes of 

 water put into rapid motion by one volume only such, 



