Theophrastus

“ Whatever may be the Case in the Vegetable and Animal Kingdoms, it is the Misfortune in the Study of fossile Bodies, that such has been the Confusion and Intermixture of their constituent Particles at the general Deluge, that there are none such to be established in them; for there are so many heterogene Particles, of a thousand different Kinds, mixed even with the same Fossil in different Places, that there is no determining to any Certainty, even its Manner of Variation from its pure State. ”

“ These, of all my Experiments on Copper, are what have afforded me the greatest Satisfaction in the Subject of the present Enquiry; as they shew, that Nature is so far from being tied to one single Menstruum for producing the Sapphirine Colour from Copper, that instead of the Colours of the blue Gems being owing only to the Effects of a single, scarce, indeed uncertain Menstruum on that Metal, we find they are producible from the Action of others, and those the most common, most abundant, and indeed, universal Menstruums of the fossile World. ”

“ Spar is one Thing, of one Weight, one Hardness, and when pure can never be mistaken for any other Fossil. It is liable to have other Bodies mixt with it; and to be altered in its Condition by that Mixture: But 'tis itself the same. Wallerius distinguithes three Degrees of Hardness in this Fossil; but they are owing to those Mixtures; the least hard is the true Condition of Spar; the other Degrees arise from Iron, or other Additions.
It is the Opinion of Linnæus, that Spar owes its angulated Form to Sea Salt; and the Crystals to other Salts: But there is no Warrant in Nature for this Judgment. ”

“ I cannot but observe, that external Appearances are of little Weight in Philosophy; and I am sorry to say, that it was only a very superficial View of these Things, that could start an Objection to Copper's colouring the Sapphire, from them: For a more careful Examination of these very Bodies, must afford Arguments for the contrary, as it will evidently prove, that the Colour of the Sapphire cannot be owing to the same Substance with that of these Glasses: Since the very Heat necessary for forming them, would, in a few Minutes, wholly divest the finest Sapphire in the World of all its Colour. ”

“ It is found in the East and West Indies, and in Germany, Silesia, Bohemia, and England; but is little valued any where.
Woodward errs in thinking our Jewellers call this the Smaragdo-Prasus: that and the Chrysoprasus are both, indeed, called Species of it, but are much superior to it in Beauty and Value. The Chrysoprasus is a Stone of greater Lustre and Hardness than the Prasius, and is in Colour of an equal Mixture of green and yellow. And the Smaragdo-Prasus, a beautiful Gem, of a grass green, with the slightest Cast imaginable of yellow. ”

“ The Antients reckoned five Species of the Amethyst, differing in Degrees of Colour; and we have at least as many among the Jewellers at present, though they are not at the pains to distinguish them by particular Names; they divide them in general into Oriental and Occidental: The former are very scarce, but of great Hardness, Lustre, and Beauty; the latter are had from many Places, particularly Saxony, Germany, and Bohemia: They are often as finely coloured as the Oriental, but are soft. In England we also sometimes find them very beautiful, and of tolerable Hardness. ”

“ When they are very rich in these Metals, they lose the Name of Marchasites, andare called Ores. The Mineral, called in some Parts of England Mundick, is of this Kind, containing Copper and sometimes other Metals; but the Sulphur is so abundant in these kinds of Ores, that they are not to be fluxed without great Trouble; the Addition of Lime, or some similar Substance, is often necessary to bring them to fuse at all, and at best they are the most troublesome, and least profitable; unless where very rich indeed, of any Ores in the World. ”

“ Sand, and the common vegetable Mould, which some give a Place in the Catalogues of Earths, have of right no Business among them; for the first is only either a smaller kind of Gravel, consisting of an infinite Number of small Pebbles of different Shapes and Colours; or the constituent Particles of the Stone of Strata or other Bodies accidentally loose: and the latter owes its present Mode of Existence, in a great measure, to putrifed animal and vegetable Substances of a thousand Kinds; and is, distinctly speaking, no genuine Fossil. ”

“ Let others therefore freely repeat these my Experiments, and add more of their own; and with an honest Freedom tell the Result of all: My single Attention can only make a few Experiments, where true Knowledge demands a thousand: But the Result of different Trials will bring forth Truth. ”

“ That the Spar formed in Fissures of Rocks, is thus washed out of the Limestone itself is certain:
Because none but Limestone Rocks have Spar in their Fissures; Rocks of Crystaline Matter, or formed of vitrifiable Stone, have Crystal; never Spar in their Cracks.
Linnæus wonders at the Nature of that Force which split the Rocks into these Cracks: But probably the Cause is very familiar; they were formed moist, and cracked in drying.
Spar grows continually; for wheresoever there is a Crack in a Limestone Rock, new, or old; Spar always fills it; and over-runs the Surface. ”

“ LXXVIII. The Nature of the Stone which tries [76] Gold, is also very wonderful, as it seems to have the same Power with Fire; which is also a Test of that Metal. Some People have, for this Reason, questioned the Truth of this Power in the Stone; but their Doubts are ill founded, for this Trial is not of the same Nature, or made in the same Manner with the other. The Trial by Fire is by the Colour, and Quantity lost by it; but that by the Stone, is made only by rubbing the Metal on it; the Stone seeming to have a Power of receiving separately the distinct Particles of different Metals. ”

“ With this Account of the Melian Earth, as white, it is very surprising that the generality of Authors, and even those of the first Class, have constantly imagined it to be yellow. The Occasion of the Mistake has been, that the Melinus Color of the Latins, Μήλινον χρῶμα of the Greeks, is yellow. This, they took it for granted, had its Origin from the Colour of the Melian Earth, a Substance antiently used in Painting, and which therefore they concluded must be yellow, and described it accordingly. ”

“ Its Particles, which are very powerful and very active, insinuate themselves into the Substance of the Matter to be melted, break and divide its Parts, and occasion a much smaller Contact of them than there was before, and of Course a weaker Cohesion: more fiery Particles continually getting in as the Matter continues on the Fire; more and more diminish the Degree of Contact, till at last there is not enough of it to keep the Particles from rolling one over another, that is coming into a State of Fusion. ”

“ How far the Heat, which is apparently manifest to our Senses at great Depths in the Earth; and is from thence, and from much greater Depths than we are ever likely to have Opportunities of being acquainted with, continually passing upwards to the Surface, may have been concerned in disspating the remaining Part of the Water, which had served to bring the Particles of Stones and Earths together ”

“ The Stone here meant, was a very bright white Substance, so nearly resembling Silver in Appearance, that it was scarce, at first Sight, to be distinguished from it: It was found in large Masses, and was of a Texture easily to be wrought into any Shape or Figure. This made it in great Esteem among the Antients, and in constant Use, turned into Vessels of different Kinds. What Stone it was, is at present not to be certainly determined, farther than that it was of the Ollaris Kind; probably it may be now lost; at least among the Nations we have Commerce with. ”

“ A Knife will scratch it: It does not readily ferment with Acids, nor will it strike Fire with Steel: It neither burns to Glass, nor Lime; but exposed to the Action of a violent Fire, it splits into thin, irregular, flaky Fragments, and by Degrees crumbles into a Kind of Powder, over which the Fire has no farther Power. ”

“ For we find evidently, that the Power of Water, as a Menstruum, depends, in many Cases, exactly on its Degree of Heat; and as it is capable of the greater Heat, the greater Weight of the Atmosphere it is pressed by, we know not to what Height its Heat and dissolving Power may be raised at great Depths in the Earth.
Of the mineral acid Menstruums, Spirit of Sea-salt, Spirit of Nitre, and Agua regia, all afford green Solutions of Copper, but with this Difference, that the Spirit of Salt gives a yellowish Green ”

“ The Amethyst loses its Colour in the Fire, like the Sapphire and Emerald: The Oriental Kind, divested of its Colour by this Means, comes out with the true Lustre and Water of the Diamond; and is so nice a Counterfeit of it, that even a very expert Jeweller may be deceived by it.
↑ The Division of the Gems into Male and Female, from their deeper or paler Colour, I have before observed, is in a Manner general, and runs through almost the whole Class: The Male is always the deeper, the Female the paler; tho' both Kinds, as they are called, are often found in the same Stone. ”

“ In fine, the Formation of Spar is yet a Subject of Enquiry: Its Atoms are all Spar; each Particle into which we can without Violence divide it, is the same in all Respects as the Whole: And as the Fossil World admits no Generation, or Birth, by Egg, or Seed, it seems most probable that all the Variety of Forms in which we see this Protean Mineral, are owing to no Cause beside the Arrangement of Rhombs into as many Forms as they are capable of producing. It fills the Cracks of its own Rocks: And of no other: For Crystal Columns rise from crystaline Rocks ”

“ The Pebble Crystals of England are often of very considerable Hardness; and some have been found here which the Lapidaries have said approached to the white Sapphire. The pointed and hexangular are what Authors have called Iris's and Pseudo-adamantes. The Antients were of opinion, that Crystal was only Water congealed in long tract of Time, into an Ice, more durable than the common. And Pliny thought it was no where to be found but in excessively cold Regions; but we are now very certain, that it is even in the hottest. ”

“ Moderns, when they would express what we call Pit Coal, the Substance here described by the Author, never use the Words ἄνθραξ or Carbo alone, but always Carbo fossilis, and λιθάνθραξ. See Woodward, Charlton, Merret, &c. The similar Use of this Bitumen got it the Name of Coal, but always with an Addition that distinguished it from what was more commonly and properly so called; and expressed its not being of vegetable, but fossile Origin. ”

“ It is not to be wondered at, that the Solutions of Copper in the fixed Alkalies produced from different vegetable Substances, are no way different from one another, since these Bodies act in these Solutions, not as the peculiar Salts of this or that Plant, but as a Body made, not by any Operation of Nature, but by the Effect of Fire ”

“ Water is the Basis of Metals; as Silver, Gold, and the rest: Earth of Stones; as well the more precious, as the common: and of the various Earths of peculiar Kinds, whether remarkable for Colour, Smoothness, Density, or whatever other Quality.
III. The Metals have been considered in another Work: the Stones and Earths of various Kinds, therefore, are to be the Subject of this Treatise.
IV. All these we are (plainly speaking) to judge formed by the Concretion of Matter pure and equal in its constituent Parts ”