NOTICE OF MARINE DEPOSITES. 
towards uniform saturation is opposed in a manner which 
must quickly draw off the salt-water from a hollow, such 
as a lake; because the surface-water, in general, is con- 
tinually changing, and the water, which has become slight- 
ly saturated, flows off, and is replaced by that which is 
purer, and has a greater attraction for the salt ; and to 
satisfy this augmented attraction, the progress of change 
downwards must be much more rapid. Consequently, how- 
ever slowly the tendency to equilibrium may act in an iso- 
lated solution, — in the other case, as the progress of ex- 
haustion goes on more rapidly, we may expect that no long 
period would be required to destroy all perceptible saltness. 
That this period has long since passed, in our Scottish 
lakes, can scarcely be doubted; but though we be not 
able to bring up sea- water from the bottom of any of them, 
yet all are interesting objects of observation. Loch Lomond 
in particular, as the additions it receives are so uniformly 
distributed over the whole space of its margin, is admirably 
fitted for experiments on the changes or stability of tern- 
perature in deep waters. 
