MALTA AND SICILY. 
49 
question, because as the water they supply is 
fresh, it may be supposed to be all lost by 
evaporation, without occasioning any deposit 
of solid matter. Now, although at the only 
visible communication with the main ocean, 
at Gibraltar, there is almost always a strong 
inward current at the surface , it has been 
supposed that at the bottom there is an 
equal flow of water from the Mediterranean 
into the Atlantic. I have never heard that 
the existence of such a counter-current has 
been proved, though it certainly would not 
be very difficult to ascertain it. But has any 
cause ever been assigned for this extraor¬ 
dinary contrary motion of the water ? 
Should it, however, be proved, that the 
waters of the Mediterranean are not dis¬ 
charged through the same channel by which 
they are received, then we may be certain 
that there exists a subterraneous passage in 
E 
