Plot 1677
R[obert] P[lot], The Natural History of Oxford-Shire, Being an Essay toward the Natural History of England, Oxford – London [Theater – Simon Miller] 1677.
Robert Plot (1640–1696) was an English naturalist and antiquary, Professor of Chemistry at the University of Oxford and, from 1683, Keeper of the Ashmolean Museum. In 1677 he also became a Fellow and Secretary of the Royal Society of London, and between 1682 and 1684 he served as a co-editor of the scientific journal Philosophical Transactions. His work The Natural History of Oxford-Shire was published in 1677; among other subjects, it contains remarks on the mining and processing of ochre on Shotover Hill near Oxford, formerly the most important ochre deposit in England.
CHAP. III.
Of the Earths.
. . .
pp. 54–58
12. But beside these, we have another sort of Earth, of a fat close texture, and greenish colour, so well impregnated with some kind of salt, that put in the fire, it presently decrepitates with no less noise than salt it self; and in water, after a quick and subtile solution, leaves behind it a kind of brackish tast, which I thought might proceed from a sort of Vitriol, and perhaps true enough, though the water would not tinge with powder of galls: it takes grease out of cloaths extreamly well, and would it but whiten, as Fullers earth doth, I should not doubt to pronounce it the same with the viridis Saponaria, found near Beichling in Thuringia, and mentioned by Kentmannus in his collection of Fossilsw. This we have in great plenty in Shot-over Forest, where ‘tis always met with before they come to the Ochre, from which it is separated but by a thin Iron crust, and may peradventure be as strickt a concomitant of yellow Ochre, as Chrysocolla (another green Earth) is said to be of Gold. At present ‘tis accounted of small or no value, but in recompence of the signal favors of its present Proprietor, the Right Worshipful Sir Timothy Tyrril, who in person was pleased to shew me the pits, I am ready to discover a use it may have, that may possibly equal that of his Ochre. Which brings me next to treat of such Earths as are found in Oxford-spire, and are useful in Trades.
13. And amongst these the Ochre of Shotover, no doubt, may challenge a principal place, it being accounted the best in its kind in the world, of a yellow colour and very weighty, much used by Painters simply of it self, and as often mix’d with the rest of their colours. This by Plinyx, and the Latines, was anciently called Sil, which we have now changed for the modern word Ochra, taken up as some think from the colour of the Earth, and the Greek word ὠχρός, Pallidus; or as others, and they perhaps more rightly, from the River Ochra that runs through Brunswick, whose Banks do yield great quantities of ity; and from whence in all likelyhood we received the name, upon the arrival of the Angles and Saxons in Britan.
wCap. I. De terræ. x Plin. Nat. Hist. lib. 33. cap. 32. y Encelius de re Metal. lib. 2. cap. 20.
14. They dig it now at Shotover on the east side of the Hill, on the right hand of the way leading from Oxford to Whately, though questionless it may be had in many other parts of it: The vein dips from East to West, and lies from seven to thirty feet in depth, and between two and seven inches thick; enwrapped it is within ten folds of Earth, all which must be past through before they come at it; for the Earth is here, as at most other places, I think I may say of a bulbous nature, several folds of divers colours and consistencies, still including one another, not unlike the several coats of a Tulip root, or Onyon.
The
1. next the turf, is a reddish earth.
2. a pale blue clay.
3. a yellow sand.
4. a white clay.
5. an iron stone.
6. a white, and somtimes a reddish Maum.
7. a green, fat, oily kind of clay.
8. a thin iron-coloured rubble.
9. a green clay again.
10. another iron rubble, almost like Smiths cinders.
And then the yellow Ochre, which is of two parts.
1. The stone Ochre, which we may also call native, because ready for use as soon as ‘tis dug: and
2. Clay Ochre, which because of the natural inequality in its goodness, they wash and steep two or three days in water, and then beat it with clubs on a plank into thin broad cakes, of an equal mixture both of good and bad; then they cut it into squares like Tiles, and put it on hurdles laid on trestles to dry, which when throughly done ‘tis fit for the Merchant.
15. Where perhaps by the way it may be worthy our notice, how different either the Ochres, or opinions of men concerning them, are now, from what they formerly were: for whereas Dioscorides (as quoted by Wormiusz) commends to our choice the lightest earthy Ochre, highly before the other of stone: We on the contrary, and not without reason, prefer the stone Ochre as far before the clay.
16. I was told of a yellow Ochre somwhere between Ducklington and Witney, that serves them thereabout for inferior uses; and met with it beside at some other places, but none so good as this at Shotover; that at Garsington being full of blue streaks, and a small parcel (that was shewn me) taken up about Pyrton intermixed a little too much with red, as if it were now in the transmutation (so much spoke of by Naturalists) by the earth and suns heat; first into Rubrick, or Ruddle, and thence at last into pnigitis, or else black chalk.
z Ol. Wormii Museum. cap. 4. a Encel. de re Metal. cap. 20
17. Now that Nature indeed proceeds in this method, I am almost perswaded by what I have found in Shotover-hill, and elsewhere near it: for within two beds next under the Ochre (nothing but a white Sand interceding) there lies another of a much redder hue, which first receiving the steams of the earth, is now in the way of becoming a ruddle, and in process of time when it grows adust, may at last make a change into a black chalk; which I should not so easily have been induced to believe, but that at Whately Towns end, near the foot of the hill, where lately some attempts were made for Coal, they met with a vein of such kind of chalk, which perhaps long before might have been nothing but ruddle, and as long before that, a yellow Ochre. But whether Nature proceed thus or no; or suppose these are not (as some have thought) the several gradations of the same individual, yet however, I shall not be guilty of mis-placing, since all three belong to the Painters Trade.
18. To which may be added a sort of Cæruleum, which in English we may render native blue, because naturally produced by the steam of some Mineral, latent under the afore-mentioned Marl at Blunds-Court, amongst which it is found in very good plenty; but yet so thinly coating the little cavities of the earth, and some other bodies (of which hereafter) to which it sticks, that no quantities can be gotten for the Painters use, for whom it would otherwise be very fit, as upon tryal has been found by the worthy Mr Stonor. Kentmannusb indeed tells us of a cinereous sort of Earth somwhere near Padua, that affords such a blue; but I guess that ours cannot be (nor perhaps is that) the immediate production of the ambient Earth, but rather of some mineral or metal below it; of which more at large in a fitter place.
b Kentman de terris, cap. 1.
19. Hither also may be referr’d a gritty sort of Umbers, found in all parts of the County where there are Quarries of Stone: a courser kind of them I met with near Witney, and a somwhat finer at Bladen Quarry; these somtimes are found in the seams of the Rocks, and somtimes again in the body of the Stone; and notwithstanding their gritty texture, yet prove useful enough to dressers of Leather. But yet a much finer than either of the former, has been lately taken up at Waterperry, in the ground, and near the House of the Right Worshipful Sir Thomas Curson, of so rich and beautiful a colour, that perhaps it might better have been placed among the Ochres, but that mix’d with Oyl, it turned darker than that they call English, and much more so than the spruce-Ochre of Shotover Forest.
20. Beside these, we have another fine Earth, of a white colour, porous and friable, insipid and without scent, dissoluble in water; and tinging it, of a milky colour, and somtimes raising a kind of ebullition in it; found frequently in the lissoms or seams of the Rocks, or sticking to the hollow roofs of them: in short, so altogether agreeable to what Conradus Gesnerc (and out of him Boetius de Boot, Calceolarius, Aldrovandus, and Olaus Wormius) calls Lac Lunæ, that I could not but think it the very same. And to put all out of doubt, I tryed the Experiment of Daniel Major (who wrote no less than a whole Treatise concerning it) and found according to him, that with Lacca, though I could get none good, it gave the skin so florid a whiteness, that I dare pronounce it a good Cosmetick, and upon that very score have given it place here.
c De figuris Lapidum. cap. 6.