Commentary Page 161



	THEOPHRASTUS ON STONES

	stones supposedly could be formed by the action of either fire or cold (sec. 3), and even by both, according to Aristotle.³⁴¹ If they were formed by cold, that is, by the departure of heat after the original matter had been highly heated, they could not be dissolved by the action of water, the cold-moist, since this could not dissolve what the cold solidified. On the other hand, heat could not dissolve them either, because heat was active in forming them. Moreover, certain stones, or stony materials such as pottery, which were supposedly formed by the direct action of fire, could not in general be softened or dissolved by fire. Neither could they be disintegrated by the action of water, because their pores, in contrast to those of earths, were so compacted in the process of formation that water could not enter and bring about their dissolution.³⁴² After an earth had been mixed with water, the mixture could be readily softened by heat, since it was thought that any kind of matter that contained a considerable proportion of water was fusible (cf. sec. 10). But the continued action of heat on a mixture of earth and water could expel the water and so lead, first, to the thickening of the mixture and, finally, to its solidification, as for example in the formation of pottery.³⁴³ By this process earths were transformed into what was stone in its essential nature, and this "stone" could not again be brought to the fluid state by the action of either fire or water. Though it was believed that most stones could not be melted by fire, certain stones were in fact observed to be fusible (sec. 9). This phenomenon was not really an exception to the doctrine that opposite effects are produced by opposite causes, since such unusual stones contained a certain proportion of residual water which caused them to be fusible.³⁴⁴ The infinitive μαλάττεσθαι is an emendation made by Turnebus and accepted by Schneider; the manuscripts have άλλοιονσθαί ("to be altered"). This emendation is very plausible, since τήκεσθαι and μαλάττβσθαυ are followed by τήκεται μ£ν and μ,αλάττεται Se in the next sentence. ³⁴¹ Op. tit., IV, 6. ³⁴² Op. tit., IV, 6, 383B; 8, 385A. ³s op. tit.,* IV, 6-7. ³ⁱOp. tit.,* IV, 10, 38815-3893.

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