These, then, were his opinions. R. P. 39 b. It is obvious that, if we can trust this passage, it is of the greatest possible value; and that, upon the whole, we can trust it is shown by the fact that it follows the exact order of topics to which all the doxographies derived from the great work of Theophrastos adhere. First we have the primary substance, then the world, then the heavenly bodies, and lastly, meteorological phenomena. We conclude, then, that it may be accepted with the exceptions, firstly, of the probably erroneous conjecture of Theophrastos as to rarefaction and condensation mentioned above; and secondly, of some pieces of Stoical interpretation which come from the _Vetusta Placita_. Let us look at the details of the theory. The pure fire, we are told, is to be found chiefly in the sun. This, like the other heavenly bodies, is a trough or bowl, or perhaps a sort of boat, with the concave side turned towards us, in which the bright exhalations from the sea collect and burn. How does the fire of the sun pass into other forms? If we look at the fragments which deal with the downward path, we find that the first transformation that it undergoes is into sea, and we are further told that half of the sea is earth and half of it πρηστήρ (fr. 21). The full meaning of this we shall see presently, but we must settle at once what πρηστήρ is. Many theories have been advanced upon the subject; but, so far as I know, no one[379] has yet proposed to take the word in the sense which it always bears elsewhere, that, namely, of hurricane accompanied by a fiery waterspout.[380] Yet surely this is just what is wanted. It is amply attested that Herakleitos explained the rise of the sea to fire by means of the bright evaporations; and we want a similar meteorological explanation of the passing of the fire back into sea. We want, in fact, something which will stand equally for the smoke produced by the burning of the sun and for the immediate stage between fire and water. What could serve the turn better than a fiery waterspout? It sufficiently resembles smoke to be accounted for as the product of the sun’s combustion, and it certainly comes down in the form of water. And this interpretation becomes practically certain when taken in connexion with the report of Aetios as to the Herakleitean theory of πρηστῆρες. They were due, we are told, “to the kindling and extinction of clouds.”[381] In other words, the bright vapour, after kindling in the bowl of the sun and going out again, reappears as the dark fiery storm-cloud, and so passes once more into sea. At the next stage we find water continually passing into earth. We are already familiar with this idea (§ 10), and no more need be said about it. Turning to the “upward path,” we find that the earth is liquefied in the same proportion as the sea becomes earth, so that the sea is still “measured by the same tale” (fr. 23). Half of it is earth and half of it is πρηστήρ (fr. 21). This