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 by the same reason given above, which is, that the
same thing would happen in marshes and other waters, which are dried
up by the heat. Again, it has been said that the saltness of the sea
is the sweat of the earth; to this it may be answered that all the
springs of water which penetrate through the earth, would then be
salt. But the conclusion is, that the saltness of the sea must
proceed from the many springs of water which, as they penetrate into
the earth, find mines of salt and these they dissolve in part, and
carry with them to the ocean and the other seas, whence the clouds,
the begetters of rivers, never carry it up. And the sea would be
salter in our times than ever it was at any time; and if the
adversary were to say that in infinite time the sea would dry up or
congeal into salt, to this I answer that this salt is restored to
the earth by the setting free of that part of the earth which rises
out of the sea with the salt it has acquired, and the rivers return
it to the earth under the sea.

[Footnote: See PLINY, Hist. Nat. II, CIII [C]. _Itaque Solis ardore
siccatur liquor: et hoc esse masculum sidus accepimus, torrens
cuncta sorbensque._ (cp. CIV.) _Sic mari late patenti saporem
incoqui salis, aut quia exhausto inde dulci tenuique, quod facillime
trahat vis ignea, omne asperius crassiusque linquatur: ideo summa
aequorum aqua dulciorem profundam; hanc esse veriorem causam, quam
quod mare terrae sudor sit aeternus: aut quia plurimum ex arido
misceatur illi vapore: aut quia terrae natura sicut medicatas aquas
inficiat_ ... (cp. CV): _altissimum mare XV. stadiorum Fabianus
tradit. Alii n Ponto coadverso Coraxorum gentis (vocant B Ponti)
trecentis fere a continenti stadiis immensam altitudinem maris
tradunt, vadis nunquam repertis._ (cp. CVI [CIII]) _Mirabilius id
faciunt aquae dulces, juxta mare, ut fistulis emicantes. Nam nec
aquarum natura a miraculis cessat. Dulces mari invehuntur, leviores
haud dubie. Ideo et marinae, quarum natura gravior, magis invecta
sustinent. Quaedam vero et dulces inter se supermeant alias._]