Page:Theophrastus - History of Stones - Hill (1774).djvu/21

 to oberve, that it was far from being either aburd, or improbable, at the Time when he wrote; when the Sciences, to which the preent Age owes its Improvements in Natural Knowledge, were o little undertood; and o few of the Experiments, which have now given Light into it, had been made; and that it carries at leat, an equal Air of Probability, with many that have been ince formed; and is abolutely more uccinctly, clearly, and philoophically delivered than any of them all.

The Principles of mixed Bodies, as well thoe of the foile, as of the vegetable and animal Kingdoms, are indeed o intimately united, and cloely combined together, at their original Formation, that we are not to wonder, an Author, who wrote in uch early Times, was not clearly acquainted with the exact Manner of their Compoition: Thoe who have followed him, even after the Dicoveries of many ucceeding Ages, and with the Aitance of Chemitry, the bet and ureft of all Means of judging, (and which, whatever ome Men of fertile Imaginations may have thought, we have no ound Reaon to believe was much known in his Time) have yet been of late found to have run into great Errors about them: and even thoe of the preent and lat Age, who have been able to dicover the Mitakes of thee, and have the Advantage of yet greater and farther Improvements in that Science, if they will peak frankly and ingenuouly, mut own, that though they have dicovered the Errors of their Predeceors, and are certain they are nearer the real Knowledge of the Myteries of Nature than thoe of any other Age have been, they yet are enible, that they are only making farther and farther Advances toward what, perhaps, it is not in human Nature ever perfectly to complete.

Chemical Analyies, when judiciouly and carefully made, are unquetionably the uret and bet Methods we can ue, towards the of Stones; as well the more precious, as the common: and of the various Earths of peculiar Kinds, whether remarkable for Colour, Smoothnes, Denity, or whatever other Quality.