Now, Dr Hutton argued, that substances precipitated from a solution, and crystallizing at liberty, cannot be supposed to impress one another in the manner here exemplified; and that they could do so only when the whole mass acquired solidity at the same time, or at the same time nearly.[146] Such simultaneous consolidation can be produced in no way that we know of, but by the cooling of a mass that has been in fusion. [Footnote 146: Theory of the Earth, vol. i. P. 104.] 289. A granite, brought from Daouria by M. PATRIN, and described by him in the Journal de Physique for 1791, p. 295, under the name of _pierre graphique_, seemed to Dr Hutton to have so great a resemblance to the granite of Portsoy, that he ventured to consider them both as the same stone, and as both containing quartz moulded on feltspar.[147] It should seem, however, from further explanations, which M. Patrin has since given, but Dr Hutton was mistaken in his conjecture, and that, in the _pierre graphique_ of the former mineralogist, the quartz gives its form to the feltspar, preserving in its crystals their natural angle of 120 degrees[148] It is impossible, I think, to doubt of the accuracy of this statement; and the graphical stone of Portsoy must therefore be admitted to differ materially from that of Daouria. They are not, however, without some considerable affinity, besides that of their outward appearance; for, though the quartz in the former is generally moulded on the feltspar, the feldspar is also occasionally impressed by the quartz, and sometimes even included in it. They may be considered as varieties of the same species of granite; and the _pierre graphique_ of Corsica is probably a third variety, different from them both. [Footnote 147: Trans. Royal Society Edin. vol. iii. p. 83.] [Footnote 148: Journal Britainnique, (of Geneva,) 1798, vol. viii. Sciences et Arts, p. 78.] 290. It would seem, however, that all these stones lead exactly to the same conclusion. M. Patrin describes his specimen as containing quartz crystals, that are for the most part only _cases_, having their interior filled with feltspar "Le feltspath en masse contient des crysteaux quartzeux, qui n'ont le plus souvent que la carcasse, et dont l'interieur est rempli de feltspath; souvent il manque à ces carcasses quelques unes de leurs faces, et souvent la section de cette pierre dans un sens transversal aux crysteaux, presente une suite de figures qui sont des portions d'hexagones, et qui ne resemblent pas mal à des caractères Hebraiques."[149] [Footnote 149: Journal Britannique, _Ibid._]