Page:The Works of Aristotle - Vol. 6 - Opuscula (1913).djvu/106

824$a$ this. Some, however, have held that the common element is that which is present in the greatest quantity, and that there is a greater quantity of water in the sea than elsewhere, and that, therefore, sea-water is the element present in all water. But water naturally has its position above the earth and is lighter than it; for we have already shown that water is at a higher elevation than the earth according to the altitude at which the mass of water stands. Let us take two vessels of the same size and place fresh water in one and salt water in the other; then let us take an egg and place it in the fresh water; it will sink, whereas, if we place it in the salt water, it will float. It therefore rises above the particles of salt water because these particles do not let it sink, as do those of fresh water, but they can uphold the weight, which therefore does not sink. So in the Dead Sea no animal can sink, nor is any animal life produced in it, because dryness predominates in it and it is like the form of earth. It is clear, therefore, that dense water finds a lower level than water which is not dense; for the dense is of the nature of earth, the rare of the nature of air; therefore, fresh water stands at a higher elevation than any other water, and is therefore further removed from earth. Now we already know that the water which is furthest removed from earth is the natural water, and we have shown that fresh water is higher in position than all other kinds of water; it therefore follows certainly and necessarily that it is the natural water. Salt water is also produced in pools, because fresh water becomes salt. The saltness, therefore, of the earth by its saltness prevails over the fresh water and the air will remain enclosed, and the mass of water will not therefore be fresh. Saltness may also be produced from water by being given off from it like sweat.