Water would not move from place to place if it were not that it seeks the lowest level and by a natural consequence it never can return to a height like that of the place where it first on issuing from the mountain came to light.  And that portion of the sea which, in your vain imagining, you say was so high that it flowed over the summits of the high mountains, for so many centuries would be swallowed up and poured out again through the issue from these mountains.  You can well imagine that all the time that Tigris and Euphrates

945.

have flowed from the summits of the mountains of Armenia, it must be believed that all the water of the ocean has passed very many times through these mouths.  And do you not believe that the Nile must have sent more water into the sea than at present exists of all the element of water?  Undoubtedly, yes.  And if all this water had fallen away from this body of the earth, this terrestrial machine would long since have been without water.  Whence we may conclude that the water goes from the rivers to the sea, and from the sea to the rivers, thus constantly circulating and returning, and that all the sea and the rivers have passed through the mouth of the Nile an infinite number of times [Footnote:  Moti Armeni, Ermini in the original, in M. RAVAISSON’S transcript "monti ernini [le loro ruine?]".  He renders this "Le Tigre et l’Euphrate se sont deverses par les sommets des montagnes [avec leurs eaux destructives?] on pent cro’re” &c.  Leonardo always writes Ermini, Erminia_, for Armeni, Armenia (Arabic:  Irminiah).  M. RAVAISSON also deviates from the original in his translation of the following passage:  “Or tu ne crois pas que le Nil ait mis plus d’eau dans la mer qu’il n’y en a a present dans tout l’element de l’eau.  Il est certain que si cette eau etait tombee” &c.]

II.

ON THE OCEAN.

Refutation of Pliny’s theory as to the saltness of the sea (946. 947).

946.

WHY WATER IS SALT.

Pliny says in his second book, chapter 103, that the water of the sea is salt because the heat of the sun dries up the moisture and drinks it up; and this gives to the wide stretching sea the savour of salt.  But this cannot be admitted, because if the saltness of the sea were caused by the heat of the sun, there can be no doubt that lakes, pools and marshes would be so much the more salt, as their waters have less motion and are of less depth; but experience shows us, on the contrary, that these lakes have their waters quite free from salt.  Again it is stated by Pliny in the same chapter that this saltness might originate, because all the sweet and subtle portions which the heat attracts easily being taken away, the more bitter and coarser part will remain, and thus the water on the surface is fresher than at the bottom [Footnote 22:  Compare No. 948.]; but this is contradicted