9. become fluid along with the material. Some preposition like σνν ("with") is missing in the Greek text. Either ρίονσι σνν ols or σνρρέονσιν 6t<s might be expected.
9. And some go so far as to say that all of them melt except marble and that this burns up and lime is formed from it.
Though Kovia has been translated as "lime," an alternate possibility is "ashes." This meaning is discussed in the notes on section 69. In that section Theophrastus describes briefly the "burning" of marble in order to make lime. He is essentially correct in noting the infusibility of marble, for most rocks, being composed of silica, silicates, or various mixtures of the two, melt at moderately elevated temperatures; but marble, which is a rock composed of nearly pure calcium carbonate, decomposes without melting at temperatures near goo° C. under ordinary atmospheric pressure. The residue, which is calcium oxide, is itself a very refractory substance that melts at about 25700 C. when it is pure; but this temperature was not available to the ancients and is not reached in modern furnaces operating on ordinary fuels. Modern investigators51 have found, however, that calcium carbonate, either in the form of the pure compound or in the form of marble, does melt when both the temperature and the pressure are high enough.
10. there are many which brea\ and fly into pieces. Theophrastus means here that some stones are infusible because, like earthenware, they contain little or no moisture. According to Plato52 the brittleness of earthenware is due to its mode of formation; for earthenware, like stone, is formed by the expulsion of water from a mixture of water and earth, followed by compression of the mass by the reaction of the surrounding air. However, in the formation of earthenware the mixture was thought to be so rapidly deprived of its water by the action of fire that the sudden violence of the compression made the product harder
61 J. W. Mellor, A Comprehensive Treatise on Inorganic and Theoretical Chemistry (London, 1923), Vol. Ill, pp. 656, 836. 52 Timaeus, 60D.
