The earth was at first mixed with water, but the increasing compression caused by the velocity of the world’s revolution made the water gush forth, so that the sea is called “the sweat of the earth,” a phrase to which Aristotle objects as a mere poetical metaphor. The saltness of the sea was explained by the help of this analogy.[614] Footnote 614: Arist. _Meteor._ Β, 3. 357 a 24; Aet. iii. 16, 3 (R. P. 170 b). Cf. the clear reference in Arist. _Meteor._ Β, 1. 353 b 11. [Sidenote: Organic combinations.] 114. Empedokles went on to show how the four elements, mingled in different proportions, gave rise to perishable things, such as bones, flesh, and the like. These, of course, are the work of Love; but this in no way contradicts the view taken above as to the period of evolution to which this world belongs. Love is by no means banished from the world yet, though one day it will be. At present, it is still able to form combinations of elements; but, just because Strife is ever increasing, they are all perishable. The possibility of organic combinations depends upon the fact that there is still water in the earth, and even fire (fr. 52). The warm springs of Sicily were a proof of this, not to speak of Etna. These springs Empedokles appears to have explained by one of his characteristic images, drawn this time from the heating of warm baths.[615] It will be noted that his similes are nearly all drawn from human inventions and manufactures. Footnote 615: Seneca, _Q. Nat._ iii. 24: “facere solemus dracones et miliaria et complures formas in quibus aere tenui fistulas struimus per declive circumdatas, ut saepe eundem ignem ambiens aqua per tantum fluat spatii quantum efficiendo calori sat est. frigida itaque intrat, effluit calida. idem sub terra Empedocles existimat fieri.” [Sidenote: Plants.] 115. Plants and animals were formed from the four elements under the influence of Love and Strife. The fragments which deal with trees and plants are 77-81; and these, taken along with certain Aristotelian statements and the doxographical tradition, enable us to make out pretty fully what the theory was. The text of Aetios is very corrupt here; but it may, perhaps, be rendered as follows:—