Notices of Memoirs—Prof Edward Hull. 165 
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I.—How tHe Waters oF THE OCEAN BECAME Salt.’ By 
Prof. Epwarp Huu, LL.D., F.R.S., F.G.S. 
|e are many things in the world around us to which we 
are so accustomed from childhood that we never stop to 
enquire why they should be so. That rivers and lakes should 
consist of fresh water, and that the sea should be formed of salt 
water, seems so natural that we consider them as not only matters 
of course, but essential to the physical economy of the world; and 
if perchance our attention is called to the fact that some inland 
lakes are formed of salt water we proceed to investigate the cause 
«f so unusual an occurrence—one which being exceptional requires 
special explanation. But how few of the thousands and millions 
who traverse the ocean or dwell upon its shores put to themselves 
the question “Why are its waters salt?” And this, notwith- 
standing that it is daily receiving supplies of fresh water both 
from the rain which falls upon its surface and from the rivers 
which empty themselves into it. Clearly there is something here 
which does require special investigation, a question which does need 
solution, because, as far as the supplies afforded by the rain and 
rivers are concerned, the ocean waters ought apparently to be fresh 
rather than salt. 
2. In using the terms “fresh” and “salt” here, and in the 
following pages, I do so in the popular sense of the words. 
Searcely any natural water, except rain, is absolutely free from 
dissolved salts. All rivers contain them to a greater or less extent, 
as do also the waters derived from wells and springs. Such waters, 
however, are called (and properly called) ‘fresh,’ which does not 
necessarily mean water absolutely devoid of salts in solution; but 
when the proportion of salts is so great as to cause the water in 
which they are dissolved to appear “salt” to the taste, then the 
term salt water or brine is applied to them. ‘The varieties of saline 
waters and the degrees of salinity are innumerable, and their pro- 
perties and uses vary accordingly. ‘There are the salt waters of the 
Dead Sea—so acrid as to be nauseous to the taste; there are those of 
the ocean, not so acrid: there are the varieties of mineral waters, 
and the brine springs highly impregnated with sodium chloride. 
But it is not necessary to go further into this branch of the subject ; 
all that is necessary is to understand clearly the meaning of the 
terms we employ, and in the following essay I shall use the words 
fresh, brackish, and salt, as applied to water in the sense they are 
popularly understood. 
3. But before entering upon the discussion regarding the cause 
or origin of the saltness of the oceanic waters we may endeavour to 
ascertain whether this highly saline character has characterised these 
waters throughout a very long period of geological time. Now 
the evidence we can safely rely upon in this part of our enquiry is 
mainly derived from the character and affinities of the organic forms 
1 Paper read at a meeting of the Victoria Institute, January 16, 1893. 
