Salt is a necessary article of food for animals, but in a far less degree than is commonly supposed.  Each of us eats on an average about ten times as much salt as we actually require.  In this respect popular notions are as inexact as in the very similar case of the supply of phosphorus.  Because phosphorus is needful for brain action, people jump forthwith to the absurd conclusion that fish and other foods rich in phosphates ought to be specially good for students preparing for examination, great thinkers, and literary men.  Mark Twain indeed once advised a poetical aspirant, who sent him a few verses for his critical opinion, that fish was very feeding for the brains; he would recommend a couple of young whales to begin upon.  As a matter of fact, there is more phosphorus in our daily bread than would have sufficed Shakespeare to write ‘Hamlet,’ or Newton to discover the law of gravitation.  It isn’t phosphorus that most of us need, but brains to burn it in.  A man might as well light a fire in a carriage, because coal makes an engine go, as hope to mend the pace of his dull pate by eating fish for the sake of the phosphates.

The question still remains, How did the salt originally get there?  After all, when we say that it was produced, as rock-salt, by evaporation of the water in inland seas, we leave unanswered the main problem, How did the brine in solution get into the sea at all in the first place?  Well, one might almost as well ask, How did anything come to be upon the earth at any time, in any way?  How did the sea itself get there?  How did this planet swim into existence at all?  In the Indian mythology the world is supported upon the back of an elephant, who is supported upon the back of a tortoise; but what the tortoise in the last resort is supported upon the Indian philosophers prudently say not.  If we once begin thus pushing back our inquiries into the genesis of the cosmos, we shall find our search retreating step after step ad infinitum.  The negro preacher, describing the creation of Adam, and drawing slightly upon his imagination, observed that when our prime forefather first came to consciousness he found himself ‘sot up agin a fence.’  One of his hearers ventured sceptically to ejaculate, ’Den whar dat fence come from, ministah?’ The outraged divine scratched his grey wool reflectively for a moment, and replied, after a pause, with stern solemnity, ’Tree more ob dem questions will undermine de whole system ob teology.’

However, we are not permitted humbly to imitate the prudent reticence of the Indian philosophers.  In these days of evolution hypotheses, and nebular theories, and kinetic energy, and all the rest of it, the question why the sea is salt rises up irrepressible and imperatively demands to get itself answered.  There was a sapient inquirer, recently deceased, who had a short way out of this difficulty.  He held that the sea was only salt because of all the salt rivers that run into it.  Considering that the