Mendes da Costa 1757
Emanuel Mendes da Costa, A Natural History of Fossils I/1, London [Lockyer John Davis – Charles Reymers] 1757.
Emanuel Mendes da Costa (1717–1791) was a British naturalist and philosopher. He came from a Sephardic family that had arrived in England from Portugal. He initially worked in a notary’s office and qualified as a scrivener (in the Scriveners’ Company). In the 1730s he began to take an interest in the natural sciences. He traded in natural materials and corresponded with Carl Linnaeus, Hans Sloane, and other scholars. In 1747 he became the first Jewish Fellow of the Royal Society in London. He later served as the Society’s secretary, librarian, and clerk. In time, however, he was accused of embezzlement and sentenced to five years in prison. After his release, he earned his living by teaching natural history. He authored several treatises in the fields of mineralogy, conchology, and botany. In his A Natural History of Fossils, published in 1757, he deals, among other topics, with coloured clays and ochres, and in explaining and distinguishing them he diverges in certain respects from his predecessors, whose contributions he subjects to criticism.
THE
NATURAL HISTORY
OF
FOSSILS.
SERIES I.
EARTHS.
. . .
p. 30
SERIES I.
CAP. I. GENUS II.
CLAYS.
Earths firmly coherent, smooth to the touch, not easily breaking between the fingers, heavy, viscid, and ductile to a great degree while moist, not readily diffusible in water, and when mixed with it, not readily subsiding from it. This genus is the most unctuous of any of this series, and hardens by fire into a kind of stoney substance.
. . .
pp. 52–53
SECT. V. The yellow Clays.
MEMB. I.
Clays which are not acted upon by acids.
I. Argilla lutea improprie ochra dicta.
YELLOW ochre and French ochre. Woodw. Cat. A. a. 75. et Cat. I. a. 30.
Ochra argillacea sordide flavescens. Hill’s hist. Foss. p. 55. Nº. 9.
This, tho’ universally called an ochre, is a genuine clay; of a fine dusky yellow colour, of a compact firm texture, moderately heavy and hard, and of an unctuous smooth surface; it slightly colours the hands, adheres slightly to the tongue, melts readily in the mouth, is soft, and leaves but little grittiness; in water it is readily diffusible, and when moist, it is very viscid and tenacious.
That sort of ochre which is commonly called French ochre, is of this kind of clay, but is finer and not so argillaceous; there are also many gradations of higher, brighter, duller or paler yellow, in the varieties of this species of clay.
In the fire it acquires a great hardness, and a fine bright red colour.
It is of great use in painting, and is sold in the colour shops of this metropolis by the names of French ochre, and spruce ochre, and when ground down by that of powder ochre.
It is dug in many places in this kingdom; and, as I am informed, in some parts of Flanders.
It is particularly dug on Shotover Hill, near Oxford; it there constitutes a stratum, says Dr. Woodward, of three or four inches thick, about 10 feet deep. Over it lies a stratum of fine pale white sand, in which numerous ferruginous Geodes’s are imbedded, and over this sand lies a white clay. It is also sometimes found in the lead mines of Flintshire and Derbyshire.
This species of clay differs in very few particulars, as has been before observed, from the Terra sigillata Strigoniensis flava, described p. 23. Nº. 3.
II. Argilla pallide flavescens.
Argilla impurior friabilis pallide flavescens. Hill’s hist. Foss. p. 26. Nº. 3.
This is a rough, irregular, impure, coarse clay, of a pale brownish yellow colour, ponderous and hard, of a somewhat loose texture, and friable; it is not in the least smooth, does not colour the hands, adheres to the tongue, melts readily in the mouth, is very astringent to the taste, but is excessive impure; in water it is readily diffusible, and leaves a great deal of grittiness at the bottom of the vessel.
It burns to a great hardness, and a pale red colour.
It is dug in many parts of this kingdom; it is used in the making of the Staffordshire and Northamptonshire coarse earthen ware, and, as I am informed, it is also one of the clays made use of in the Delft manufactory.
III. Argilla coloris pallide Straminei.
This is of a loose texture, rough or without any smoothness, light and friable, it is of a pale straw colour, it slightly colours the hands, does not adhere to the tongue, melts readily in the mouth, and is very impure; in water it diffuses somewhat slowly.
Burnt, it acquires a fine red colour, and becomes quite friable.
It is found in Dover Cliffs in Kent.
pp. 53–54
SECT. V. MEMB. II.
Alcaline Clays.
IV. Argilla fusco-lutea.
OCHRA Argillacea luteo-fusca levis. Hill’s hist. Foss. p. 55. Nº. 10.
This, tho’ an impure clay, is of a fine texture, of a dusky brownish yellow colour, very light, and of a slightly smooth surface; it is friable, slightly colours the hands, adheres firmly to the tongue, melts freely in the mouth, and leaves a great deal of grittiness. In water it raises a great ebullition, but is not readily diffusible, and when moist, is exceeding viscid and tenacious.
Burnt, it acquires a great hardness, and a fine red colour.
I have never yet observed this clay in a regular stratum, but have hitherto only found it in irregular lumps, chiefly in great plenty in the clay pits near Blackheath and Deptford; I have also found many ferruginous Geodes’s near the great sand pit at Woolwich filled with this clay.
It is not as yet used in painting, tho’ I am persuaded it will prove a valuable colour, having a good body, and being of an agreeable, tho’ dusky yellow.
. . .
pp. 89–91
SERIES I.
CAP. II. GENUS II.
OCHRES.
Earths slightly coherent, ponderous, composed of fine particles, rough to the touch, and readily diffusible in water.
SECT. I. The Black OCHRES.
MEMB. I.
Ochres which are not acted upon by acids.
I. Ochra nigra argillacea.
AN Creta nigra mollis. Kentm. Nom. Foss. p. 8. Nº. 11?
Ochra nigricans argillacea. Worm. Mus. p. 17. Charlt. de Foss. p. 219. Nº. 4.
Killoia molliuscula. The softer killow. Merret’s Pin. Rer. Nat. Brit. p. 218. Woodw. Meth. of Foss. p. 2. Nº. 5. et Cat. C. a. 26. et 27.
Humus nigra pictoria, Atramentum scissile. Wallerius’s Mineralogy, species 4.
Argilla nigrescens friabilis levis. Hill’s Hist. Foss. p. 34. Nº. 1.
Lapis cæruleus anglicus, Killow dictus. Charlt. de Foss. p. 262.
Argilla nigra de Dietfurter-riet. Bruckm. Epist. Itin. Cent. ii. Ep. 94. p. 1197. Nº. 26, et 27.
An Nigrum fossile Voigtbergense. Mus. Richt. p. 143?
Terra mollis, tenuis, nigra. Bruckm. Epist. Itin. Cent. iii. Ep. 9. p. 82. Nº. 76.
This ochre is of a fine black colour, with a bluish cast; when fresh dug it is greasy to the touch, and always retains a slight smoothness on its surface, it is very light, of a very loose friable texture, and colours the hands greatly, it adheres to the tongue, melts freely in the mouth, and has a disagreeable vitriolic taste, caused by the parts of that salt with which it is generally impregnated, and is impure, or leaves some grittiness between the teeth; in water it raises a great ebullition, and immediately breaks into a very fine powder.
In the fire it acquires some hardness, and burns to a grey colour.
It is found in great plenty on the side (near the top) of Cay Avon, a high hill near Dynasmondhwye, a village in Merionethshire, which place has long been famed for it, as is evident from an old British proverb, which says, it is one of the three remarkable things of that place. The rocks thereabouts also abound with a vitriolic marcasite. The inhabitants of that place, who call it Nod dû, which in the Welsh language signifies a black mark, prepare it by beating it in a mortar, and wetting it, and then make it up into balls, and use it in marking the sheep.
Dr. Merret informs us, it is also found in Lancashire.
At Dietfurter-riet in the territory of Pappenheim, in Germany, the inhabitants prepare it by carefully washing away the gritty parts, and then make it up into sticks, or rolls like Indian ink, and it is in like manner used in painting.
Bruckman also mentions it to be found in Saxony, where it is called Schiefer Schwartz, and is greatly used in painting.
Wormius received his ochre from the silver mines in Norway; and Wallerius mentions it to be found near Huneberg, in the province of Westergyllen in Sweden.
Tournefort’s Voyage to the Levant, Letter x. mentions a very fine black earth altogether insipid, found about Carlovassi in the island of Samos; which, says that author, as it serves to dye sowing-thread of a black colour, seems to partake of vitriol. The said earth is probably of this kind of ochre.
The English name of collow or killow, given to this ochre, according to Dr. Woodward is derived from its resemblance to the grime or smut on the back of chimneys, which is called collow in the north of England.
II. Humo-ochra, Creta nigra dicta.
Pnigites s. Creta nigra. Aldrov. Mus. Met. p. 259. Matth. p. 1392. Imperat. Hist. Nat. l. iv. c. 41. Worm. Mus. p. 5. Charlt. de Foss. p. 220. Nº. 8. Kundm. Prompt. p. 302. Nº. 135. Dale’s Pharm. p. 20. Nº. 5. Bruckm. Epist. Itin. Cent. ii. Ep. 95. p. 1208. Nº. 25. et Cent. iii. Ep. 2. p. 16. Nº. 9. et 11.
Terra nigra Randrusiensis. Worm. Mus. p. 5. Charlt. de Foss. p. 219. Nº. 6.
Terra pnigitide nigræ simillima, quam cretam nigram vocant. Mercat. Met. Vat. p. 19. et 23.
Creta nigra, nigritis, melana. Bruckm. Epist. Itin. Cent. iii. Ep. 2. p. 14.
Killoia duriuscula. The harder Killow or marking stone. Woodw. Meth. of Foss. p. 3. Nº. 12.
Terra atri coloris. Woodw. Cat. L. a. 6.
Lapis cæruleus ducendis lineis idoneus. Merretti.
Pseudo-ochra levis nigrescens, quæ creta nigra pictorum. Hill’s Hist. Foss. p. 66. Nº. 2.
Fissilis mollior, friabilis, pictorius, nigrica. Creta nigra. Wallerius’s Mineralogy, species 71.
This is a light hard earth, of a fine black colour, of a close firm regular texture, and has a slight flakey appearance; of a dry dusty surface, and colours the hands; it adheres firmly to the tongue, melts difficultly in the mouth, has a slight vitriolic taste, and is a little impure; in water it raises an ebullition, but very difficultly breaks in it.
When put into the fire it readily ignites, but does not continue burning, and becomes a fine white, and very soft substance, exactly like wood ashes.
This calcined matter yields, says Hill, a small quantity of an alcaline salt, and the experiments shew the substance itself to be partly of vegetable, partly of fossil origin.
Wallerius reckons this earth to be no other, than a destroyed slate.
It is found in many parts of Germany, at (Steinach in the duchy of Coburg, in Saxony; it is dug in masses of six pounds weight or more,) in Switzerland and Italy, particularly about the city of Milan.
It is greatly used in painting.
The Creta fuliginei coloris of Worm. Mus. p. 5. is probably referable to this species of ochre.
p. 91
SECT. I. MEMB. II.
Alcaline Ochres.
III. Ochra nigra alcalina.
THIS is a very heavy ochre, of a fine black colour, moderately hard, of a compact regular texture, of a harsh, dry, and dusty surface, and colours the hands very much; it adheres slightly to the tongue, melts freely in the mouth, has no remarkable taste, and is somewhat impure; thrown into water, it raises a strong ebullition, and immediately breaks into a very fine powder.
It raises a violent effervescence with aqua-fortis.
It remains a great while unchanged in the fire, but at last burns to a pale red colour, with no additional hardness.
I received this ochre from the slate quarries near Oberhassel in Switzerland.
pp. 91–93
SECT. II. The Red Ochres.
MEMB. I.
Ochres which are not acted upon by acids.
I. Ochra dura ponderosa rubra.
THIS is a very heavy and hard ochreous iron ore, of a fine deep red colour, of a firm compact solid texture, of a harsh, dry, and very dusty surface, and greatly colours the hands; it very slightly adheres to the tongue, melts slowly in the mouth, and is very impure; it raises an ebullition, but very difficultly breaks or moulders in water.
Burnt, it suffers no change.
It is dug in Warwickshire, and is much used in painting.
II. Ochra friabilis ponderosa rubra.
Ochra rubra friabilis ponderosa, sil syricum antiquorum. Hill’s hist. Foss. p. 57. Nº. 1.
This is of a fine strong red colour, very weighty, of a loose friable texture, and of a very rough and dusty surface; it colours the hands greatly, adheres firmly to the tongue, melts freely in the mouth, has a strong astringent taste, and is very impure or full of grittiness; in water it raises a great ebullition, and immediately moulders into a fine soft powder.
In the fire it acquires a considerable hardness, and a much paler colour.
It is dug in many parts of England, and is much used in painting.
III. Ochra Indica saxea purpureo-rubra.
Stone colour from the East Indies. Woodw. Cat. I. a. 38.
Ochra saxea rubra, quæ sil marmorosum antiquorum. Hill’s Hist. Foss. p. 62. Nº. 13.
This is a heavy and very dry hard stoney ochre, of a fine purplish red colour, of a very compact and solid texture, and quite like a metallic ore; its surface is rough and dusty, and it colours the hands; it adheres firmly to the tongue, melts with extreme difficulty in the mouth, and breaks or moulders as difficultly in water.
The pieces of this ochre generally have small cavities, in which I have frequently observed pieces of potters lead ore, and also pieces of a bright dazzling mock ore.
It suffers little change in the fire, the colour rather becoming more dusky.
It is brought to us from the East Indies: there are several considerable strata of it, says Hill, on the borders of China.
It is of great use among the painters, it being a very valuable colour, and by them is called the Indian stone red.
IV. Ochra levis purpurascens.
Ochra purissima levis purpurascens. Hill’s Hist. Foss. p. 60. Nº. 8.
This is of a very fine purple colour, light and friable, of an even and regular texture, of a dusty surface, and colours the hands; it adheres firmly to the tongue, melts freely in the mouth, is quite pure, and of a strong astringent taste; in water it raises a flight ebullition, but does not readily moulder away.
It suffers little change in the fire.
It is common in the perpendicular and horizontal fissures, where there is iron ore, especially in the forest of Dean, in Gloucestershire.
The earths exhibited by Woodward, Cat. c. a. 7, 8, and 9. (“red loose earths, very fine; found in an iron mine in the forest of Dean. This sort is found found generally near the ore, in the inclining fissures: the workmen save it, and call it red ochre,”) are of this species.
The said author likewise exhibits, Cat. A. a. 90, et 91. earth, very fine, and of a bright red, preferable to that brought from the East Indies for the use of painters, found in a fissure, among iron ore, in the Skrees, a mountain in Cumberland; ’tis a red ochre: and red ochre from Staffordshire, which both are probably of this very species of ochre.
pp. 93–97
SECT. II. MEMB. II.
Alcaline ochres.
V. Ochra fusco-rubra, quæ rubrica Sinopica antiquorum.
RUBRICA sinopica s. Sinopis pontica. Hill’s Theophr. p. 126. Diosc. l. v. c. 111. Pliny Hist. Nat. l. xxxv. c. 6. Avicen. l. xi. tract. 2. c. 428. Matth. p. 1359. Salmasius’s Exercit. Plin. Imperat. Hist. Nat. l. iv. c. 3. et 4. et l. v. c. 19. Tournefort’s Voyage to the Levant, vol. ii. Letter v. Dale’s Pharm. p. 19. Nº. 6. Mercat. Met. Vat. p. 13. et p. 23.
Ochra purpurea purissima ponderosa, quæ rubrica sinopica antiquorum. Hill’s Hist. Foss. p. 60. Nº. 9.
This is a fine pure earth, quite free from any grittiness, of a brownish red or liver colour, very weighty, but not very hard, of a dense compact texture, of a dusty surface, and colours the hands; it adheres firmly to the tongue, melts slowly in the mouth, is astringent to the taste, and when thrown into water, spreads and diffuses itself greatly.
In the fire it acquires a great hardness, but does not change colour.
It was anciently found in Cappadocia, and was constantly carried to Sinope for sale, from whence it obtained its name Sinopis: it was also found in Egypt, and in the Baleares islands, which are at present called Majorca and Minorca. Strabo likewise says, as good rubrica as the sinopic, was brought from Turditania, which is now the kingdom of Algarve in Portugal, and that that of Spain, which very likely is the almagra, hereafter to be described, was as good.
Imperatus and Mercator affirm this ochre to have been brought into Italy, in their times, from Constantinople, in some quantity, and that it was called, tho’ erroneously, Bolus armenus orientalis.
Mercator informs us, he found three kinds of rubricæ in the iron mines of the island of Elba, on the coasts of Tuscany, in the veins of the iron ore, and also lodged in the horizontal fissures: the first sort was the true rubrica sinopica, of a liver colour; the second sort was not of so fine or strong a colour; and the third sort was the rubrica fabrilis, or common rubrica.
Hill says, that he has received it from the New Jerseys in America, where it is frequently found in digging at about fifteen or twenty feet deep, and is vulgarly called blood-stone.
It was anciently used in medicine, and held in great esteem as an astringent in fluxes and hæmorrhages of all kinds.
It was likewise held in great esteem for painting, and was one of the four primitive colours, viz. the red, of the great painters of antiquity.
VI. Ochra Hispanica almagra dicta.
Ochra purpurea friabilis alcalina, almagra recentiorum, sil atticum antiquorum. Hill’s hist. Foss. p. 57. Nº. 2.
This is of a fine deep red colour, with a cast of purple, weighty, not hard, but easily crumbles between the fingers, of a moderately dense, compact, and regular texture; harsh and rough to the touch, of an extremely dusty surface, and colours the hands very much, it adheres firmly to the tongue, melts freely in the mouth, is astringent to the taste, and very impure; in water it raises a great ebullition, and immediately breaks into a very fine powder.
Burnt, it acquires a paler colour, and a considerable hardness.
It is dug in great quantities in many parts of Spain, chiefly in the kingdom of Murcia; particularly at the foot of the mountain of Almasaron, a town in that kingdom; the Spaniards call it Almagra, which word in the Arabick language signifies red.
It it greatly used in painting, and is to be found in the colour-shops of this metropolis, by the name of Spanish brown.
VII. Ochra elegantissimè rubescens.
Ochra friabilis levis pallide rubescens alkalina. Hill’s hist. Foss. p. 59. Nº. 6.
This ochre is of a fine bright red colour, light, easily friable, of a loose texture, of a rough dusty surface, and colours the hands greatly; it adheres firmly to the tongue, does not melt very freely in the mouth, is of a sub-astringent taste, and very impure, and breaks or moulders very difficultly in water.
It acquires no hardness in the fire, and burns to a duller colour.
This ochre I received from Dr. Hill, and have never seen it elsewhere; he informed me, that it was found in Florida, at about forty feet depth, in digging after an imaginary gold mine: the Doctor also surmises, it may probably be found in many other parts of America.
It is a valuable colour, and deserves being carefully sought after.
VIII. Ochra purpurea Persica.
Ochra purpurea ponderosissima dura. Hill’s Hist. Foss. p. 58. Nº. 3.
Woodw. Cat. I. a. 36, et 37. Pomet des Drogues, p. 115. Valentin. Aurifod. Med. p. 7. Bruckm. Epist. Itin. Cent. iii. Ep. 9. p. 80. Nº. 40.
This is of a fine purple colour, extremely heavy, and of a very great hardness; of a firm compact solid texture, and always full of bright glittering particles, of a rough and dusty surface, and colours the hands very much; it adheres very firmly to the tongue, melts difficultly in the mouth, and is of a rough austere and very astringent taste; thrown into water, it makes a very considerable ebullition, but moulders or breaks very difficultly in it.
In the fire it burns to a greater hardness, with very little change of colour.
This earth is got in great quantities, in the island of Ormuz, in the Persian gulph, and is carried thence to Surat, Bengal, and other parts of India; where it is used in painting of houses, ships, &c.
It is greatly used in painting, and is called the Indian red.
IX. Ochra rubra Bolus Veneta dicta.
Ochra friabilis pallide rubescens, quæ Bolus Veneta vulgo. Hill’s Hist. Foss. p. 59. Nº. 5.
The true Venetian bole. Woodw. Cat. I. w 9.
This is of a dull red colour, moderately heavy, of a pretty firm even texture, and easily crumbles between the fingers, of a dusty surface, and colours the hands; it adheres firmly to the tongue, melts freely in the mouth, is slightly astringent to the taste, and is very impure; in water it immediately breaks into a fine powder.
Burnt, it acquires a duskier colour, and a considerable hardness.
It is brought from Venice, and is a colour greatly esteemed among painters.
Hill errs in saying this ochre makes no effervescence with aqua-fortis, for it effervesces very considerably with that acid.
X. Ochra purpureo-rubra.
This is a very valuable and elegant ochre, of a fine deep purplish red colour, of a firm compact regular texture, easily crumbling between the fingers, moderately heavy, of a rough, harsh, dusty surface, and colours the hands greatly; it adheres firmly to the tongue, melts slowly in the mouth, is somewhat impure, and moulders or breaks difficultly in water.
It burns to a considerable hardness, with very little change of colour.
It is sometimes found, but in small quantities, in loose powder, and also concreted into small lumps, in some clay pits at Theale, four miles from Reading in Berkshire.
It is a very fine ochre for the painters use, and deserves carefully to be sought after.
XI. Ochra sordide rubra.
This is of a deep dull brown red colour, very weighty and hard, of a firm, compact, solid, regular texture, of a harsh, rough, and dusty surface, and greatly colours the hands; it does not adhere to the tongue, melts slowly in the mouth, is very astringent to the taste, and pure; in water it slowly breaks into a fine powder.
Burnt, it acquires a great hardness, and a very dull purplish red colour.
It is dug in Yorkshire, and is there called reddle.
XII. Ochra rubra ponderosissima.
This is of a very deep brown-red colour, extremely heavy, of a compact firm regular texture, but is easily broken between the fingers; of a very rough, dusty surface, and colours the hands very much; it adheres slightly to the tongue, melts freely in the mouth, is of a strong astringent taste, and a little impure; in water it immediately breaks into a fine powder.
It suffers very little alteration in the fire.
It is dug in several parts of this kingdom, and is greatly used by painters.
XIII. Ochra rufa.
Rust-coloured terra lapidosa. Plot’s Nat. Hist. Oxfordshire. Ch. iii. § 51. p. 67. Lister de Fontib. Med. Angl. p. 26.
This ochre is most generally found in powder; it is harsh, of a rust colour, and colours the hands greatly; it is moderately heavy, impure, and insipid to the taste.
When found concreted into lumps, it is of a loose friable texture; slightly adheres to the tongue, melts difficultly in the mouth, and breaks very difficultly in water.
In the fire it burns to a fine brown red colour.
It is not as yet used in painting, but I am persuaded it would prove a good colour, and quantities of it might be easily procured.
It is found very frequently pitched in round cavities in the solid chalk strata in the chalk pits of Surry, Kent, Buckinghamshire, and Oxfordshire; the chalk diggers have a very just and philosophical notion of the origin of this ochre, which they call iron moulds, and affirm it to proceed from the dissolution, or decomposition of the irony vitriolic pyrites, which they also vulgarly call iron moulds; and which so greatly abound in the chalk. I have often with great pleasure observed these ochreous masses, of a striated texture, while yet lodged in the chalk, exactly like the texture of that pyrites, also pyritæ half decompounded, the other half being yet solid pyrites; and pyrites which were mere crusts, quite filled with this kind of ochre.
I have likewise received it from a lime-stone quarry near Bath, where it is found in small veins and patches in the fissures of the quarry.
The yellow earth from Ystimtean mines, in Cardiganshire, exhibited by Woodward, Cat. C. a. 4. and which, the Doctor says, was found hanging down in form of stalactite, from the top of an anciently worked lead vein there (there were more at the top, and on the sides of this work,) is this species of ochre: as is likewise his brown earth, Ibid. a. 5. To this very species is also to be referred, his specimen a. 6. ibid. which he says, is commonly found incrustated on sticks, rushes, &c. in vast quantities, in the coal work of Billymill-Moore-level, in Northumberland, and, Cat. E. a. 1. from Rose Park in Cumberland; the Doctor further adds, that the like ochre is frequently observed in the adits of coal pits, in Cumberland, Northumberland, and Yorkshire.
The ochreous earths likewise exhibited by the said author, Cat. E. a. 2. et a. 13. from chalk-pits in Kent, and Buckinghamshire, are of this very species.
Leopold, in Itin. Suecico, p. 70. exhibits a Terra martialis ruffa, vel cinamomo in pulverem redacto similis, which is dug at the village Skeden, in the parish of Multrad, in the province of Angermannia in Sweden, which probably is of this species.
pp. 97–100
SECT. III. The Yellow Ochres.
MEMB. I.
Ochres which are not acted upon by acids.
I. Ochra argillacea flava.
OCHRA ponderosa dura pallide flavescens. Hill’s Hist. Foss. p. 51. Nº. 2.
A clayey ochre, of a very fine deep yellow colour, heavy, very hard, of a close compact firm texture, of a smooth surface, without the least roughness or dustiness, and does not colour the hands; it adheres firmly to the tongue, melts slowly in the mouth, is pure, or free from grittiness, and difficultly moulders or breaks in water.
Burnt, it acquires a fine deep colour, without any hardness.
It is dug on Mendip hills in Somersetshire, and is much used in painting, it proving a fine colour.
II. Ochra friabilis pallide flavescens.
This ochre is very fine, of a pale but very agreeable yellow colour, moderately heavy, of a very loose friable texture, of a dusty even surface, and colours the hands greatly; it does not adhere to the tongue, melts freely in the mouth, is of an astringent taste, and somewhat impure; in water it immediately breaks into a fine powder.
In the fire it acquires no hardness, and burns to a fine rose colour.
It is dug in many places in Saxony, and is greatly esteemed by the German painters.
III. Ochra Italica lutea.
Of a fine yellow colour, of a firm compact regular texture, is easily broken between the fingers, and is very light; its surface is very dusty, and colours the hands; it does not adhere to the tongue, melts slowly in the mouth, has an astringent taste, and is impure; and breaks or moulders difficultly in water.
Burnt, it acquires a considerable hardness, and a dull red colour.
It is dug in several parts of Italy, and is much used by the painters of that country.
IV. Ochra ponderosa pulchre flava.
This is a coarse ochre, of a fine bright yellow colour, heavy, hard, of a firm, compact, and very irregular texture; of a harsh, rough, dusty surface, and colours the hands; it does not adhere to the tongue, melts freely in the mouth, and is extremely impure; in water it immediately falls into powder.
In the fire it acquires no hardness, and burns to a very pale ashen red colour.
This kind is dug on Mendip hills in Somersetshire, and is greatly used by the painters.
V. Ochra pallide lutea.
A very fine ochre, of a very pale yellowish colour, of an even and regular texture; it is moderately heavy, and very easily crumbles or breaks between the fingers; its surface is dusty, and colours the hands; it adheres to the tongue, melts freely in the mouth, is very impure, and it slowly breaks in water.
Burnt, it acquires a considerable hardness, and a fine strong pink colour.
This ochre is found in a limestone quarry at Steery Way, near Wellington in Shropshire; the stratum of it is about one foot thick, and lies above the stone, about four yards below the surface.
VI. Ochra lutea.
This is of a fine high yellow colour, light, friable, of a loose regular texture, of a dusty surface, and colours the hands; it adheres to the tongue, melts freely in the mouth, and is quite pure, or free from grittiness; in water it immediately breaks into a fine powder.
Burnt, it acquires some hardness, and a fine bright red colour.
This ochre is sometimes found in the Derbyshire and Flintshire lead mines.
VII. Ochra crocei coloris.
Ochra crocea laminata levis, quæ ochra Attica Dioscoridis. Hill’s Hist. Foss. p. 35. Nº. 5.
This ochre is of a fine deep but bright yellow, like that which saffron gives to water, and sometimes is found slightly spotted with red. It is remarkably light, of a soft shattery friable texture, and generally of a laminated structure; its surface is rough and dusty, and it colours the hands, it adheres to the tongue, melts freely in the mouth, and is quite pure; in water it raises a great ebullition, but does not readily moulder away in it.
Burnt, it acquires a dusky red colour, without any hardness.
This ochre is found sometimes constituting a stratum of itself, at other times lodged in perpendicular fissures, and at other times concreted into loose nodules, and lodged in other strata.
It is found in several parts of this kingdom, as in Northamptonshire, Staffordshire, and about London.
Kentm. Nom. Foss. p. 8. Nº. 3. exhibits an Ochra nativa crocei coloris Vratislaviensis, Mercat. Met. Vat. p. 23. an Ochra nativa crocei coloris ex agro Balneoregiensi; and Bayer Oryctogr. Norica, p. 14. and Bruckm. Epist. Itin. Cent. iii. Ep. 4. p. 26. Nº. 9. exhibit a fine lemon coloured ochre, which burns red, found in great plenty near Petzensteiner Hûll, a village in the territories of the city of Nuremberg; and which is carried from thence in great quantities to various parts of Germany; all which ochres are probably of this very species.
VIII. Ochra aurei coloris.
Ochra levis aurea friabilis, quæ ochra Theophrasti. Hill’s Hist. Foss. p. 52. Nº. 4. and his Theophr. p. 125.
This is of a very fine and strong, tho’ not deep yellow colour, light, of a loose friable texture, of a harsh, dusty surface, and colours the hands; it adheres firmly to the tongue, melts freely in the mouth, is quite pure, and in water does not readily break or fall into powder.
In the fire, it burns to a very elegant red colour, with a little additional hardness.
This ochre is chiefly found in loose nodules in other strata, and sometimes also in the perpendicular fissures of mines.
It is found in several parts of this kingdom; Hill says, on Mendip hills it is common in the fissures of the mines there, and that it is likewise found in a gravel pit on the right hand side of the Oxford road, about a mile from London, where there is always great plenty of it, in lumps of four, five, or six ounces weight, and also contained in the ferruginous crustated geodes’s, which abound in that pit.
The specimen exhibited by Dr. Woodward, Cat. C. a. 3. is this very species of ochre, and which he notes, is commonly found in the fissures of the iron mines, in the forest of Dean, near the ore.
An Ochra aurei coloris, is exhibited in the Mus. Richt. p. 143. but as that author gives no description of it, it remains doubtful whether it is of this species or not.
Hill further says, he has observed this ochre in some places hanging to the sides, and from the tops of old mines, or other cavities, something resembling rude Stalactitæ, and also not unfrequently in masses of three or four ounces weight, in beds of chalk: in this latter assertion he is very erroneous; for I am convinced he never found this ochre in any chalk stratum; what I imagine he means, is, the rust coloured ochre, or Ochra rufa, already described, and which is found in quantities in the chalk pits of Surry, Kent, Buckinghamshire, and Oxfordshire; but that ochre is so greatly alcaline, as to raise a violent effervescence with acids, whereas this species is not at all acted on by them; which added to the different appearances, and other qualities of these two ochres, must certainly determine any judicious naturalist, to allow them to be two very different species.
p. 100
SECT. III. MEMB. II.
Alcaline Ochres.
IX. Ochra rufo-flava.
OCHRA Anglica. Worm. Mus. p. 17. Merret’s Pin. Rer. Nat. Brit. p. 218. Charlt. de Foss. p. 219. Nº. 5. Woodw. Cat. A. a. 76, et 77. and Cat. L. a. 21. Bruckm. Epist. Itin. Cent. iii. Ep. 3. p. 24.
Ochra Romana. Woodw. Cat. I. a. 29.
An Ochra Stanni fulva Anglica. Linnæus’s Syst. Nat. p. 205. Nº. 6?
Ochra ponderosa flava friabilis. Hill’s Hist. Foss. p. 54. Nº. 6.
This is a hard heavy ochre, of a very deep or brown yellow colour, of a firm, compact, regular texture; of a harsh, rough, dusty surface, and colours the hands greatly; it adheres to the tongue, melts freely in the mouth, and is impure; in water it immediately breaks into a fine powder.
In the fire, it acquires a little hardness, and a dusky purplish red colour.
It is dug in Somersetshire near Bristol, and also in Monmouthshire, where it is made up into large balls, and great quantities of it are yearly exported to foreign parts.
Dr. Woodward found this ochre in a lead mine in Arkendale, in Yorkshire, also in a coal pit near Cockermouth, in Cumberland, where it was deposited in cavities at the bottom of the adit, over which the water passed. It is common, says the Doctor, in the adits of many of the coal pits in the North, and I take it to be the ochreous part of the coal drained out by the water.
The said Gentleman exhibits this same kind from near Rome, where it is got in great quantities; and he also received it from New England.
The Ochra Islandica of Worm. p. 17. Charlt. de Foss. p. 219. Nº. 5. and Bruckm. Epist. Itin. Cent. iii. Ep. 4. p. 24. by Wormius’s description, seems to be this species of ochre.
Bruckm. Epist. Itin. Cent. iii. Ep. 4. p. 26. Nº. 11. exhibits an Ochra obscure flava, which, with many other kinds of ochres, are dug in the Rammelsberg mountain, near Goslar; and are also found deposited by the waters in the adits of the mines there. These ochres, says that author, are washed and prepared for use by the miners of that place; and are esteemed next to the English ochre. Kentm. Nom. Foss. p. 8. Nº. 1. and Behrens Hercynia Curiosa, also make mention of them. Probably their Ochra obscure flava, is of this very species.
pp. 101–103
SECT. IV. The Brown Ochres.
MEMB. I.
Ochres which are not acted upon by acids.
I. Ochra fusca Terra Umbria dicta.
TERRA s. Creta Umbria. Imperat. Hist. Nat. l. iv. c. 5. et 44. Worm. Mus. p. 4. Charlt. de Foss. p. 219. Nº. 7. Woodw. Meth. of Foss. p. 4. Nº. 18. et Cat. I. a. 25. et 26. Valent. Aurifod. Met. p. 6. Kundm. Prompt. p. 302. Nº. 124. Bruckm. Epist. Itin. Cent. iii. Ep. 5.
Ochra pallide fusca levis, quæ Umbria pictorum. Hill’s Hist. Foss. p. 63. Nº. 1.
Alana gleba. Mercat. Met. Vat. p. 14. et 23.
Terra subfusci coloris, quæ a pictoribus vocatur Terra d’Ombra. Mercat. Met. Vat. p. 23.
Umbra Anglica colore subfusco. Mus. Richt. p. 143.
Humus nigro-brunea, Umbra auctorum, Creta Umbria. Wallerius’s Mineralogy, species 3.
This is a very light ochre, of a fine pale brown colour, of a close, compact, and regular texture, and breaks easily between the fingers; of a dry, even, and slight dusty surface, and colours the hands a little; it adheres firmly to the tongue, melts slowly in the mouth, has an astringent taste, is very pure, or quite free from any grittiness, and slowly breaks or moulders in water.
Burnt, it becomes of a deep reddish brown colour, but acquires no hardness.
This ochre was anciently found in the greatest plenty in Umbria, now the dukedom of Spoleto, in the Papal territories, from whence it originally derived its name, and it yet continues to be brought us thence.
Umbre is now chiefly dug in the Turkish dominions. In Cyprus it is found in great quantities.
It is likewise found in many parts of Germany, as at Annaberg, Scheibenberg, and Schwartzenberg in Saxony, near Steinach in the duchy of Coburg, in the duchy of Blackenburg, and also near the mines of Sahlberg in Sweden.
In this kingdom it is sometimes found, tho’ very rarely, in the veins of lead ore. I have met with it in the lead mines of the Peak in Derbyshire, in small lumps, lodged with the deep brown ochre, next to be described. I have likewise received it from the lead mines in Flintshire; and Hill affirms, he has collected it on Mendip hills in Somersetshire.
It is greatly used and esteemed by the painters.
Imperatus imagines this ochre to have been the Achaian sil of the ancients.
Mercator and the Mus. Richt. make it the Alana gleba of the ancients.
Those authors, especially the former, say, that tho’ the accounts of the Alana gleba of the ancients are very obscure, and only P. Ægineta informs us it had the virtues of the Armenian bole, yet as we find this species of ochre among the Vallachians, which were the Alani of former times, and that those people use it in pestilential and other fevers (the effects of which, says he, I have also tried with success) I conclude this ochre probably to be the said Alana gleba of the ancients.
Wallerius ranks the Umbre as a humus or mould, but I think erroneously; that author imagines, that by its immediately flaming in the fire, and by the smell which it then sends forth, that it owes its colour to an admixture of bituminous parts.
II. Ochra friabilis nigro-fusca.
Woodw. Cat. A. a. 65, 67, 68, et 69. et Cat. C. a. 2. et 25.
An Umbra Anglica fusci coloris, Mus. Richt. p. 143?
A very light, friable, and exceeding fine ochre, and consists of parts extremely small, subtile, and even impalpable; of a loose regular texture, and of a very deep blackish or dark brown colour; it is often variously blended with veins of a yellow ochre, and thick set with glittering sparry particles.
Its surface is even, tho’ very dusty, and it colours the hands greatly; it adheres firmly to the tongue, melts pretty freely in the mouth, and raises a pretty strong ebullition in water, but does not readily break into powder.
In the fire it acquires a great hardness, and a deep blueish black colour.
I have observed this ochre in some quantity, in the veins of lead ore, in the Peak in Derbyshire, especially at Portaway lead mine, near Winster, where the miners vulgarly call it black wadd; I have likewise received it from the lead mines in Flintshire, and Dr. Woodward found it plentifully in a vein of lead ore at Totter Gill, Intacks Nook, in Arkendale in Yorkshire; the Doctor likewise collected it in a fissure of a mountain near the Skrees, and in large masses upon the top of another mountain in Cumberland, also in a lead vein, at the top, near the surface, in one of the Companies mines, called Bwlch Kaninog, in Cardiganshire, and in a sinus of a rocky cliff, betwixt Tenby and Milford in Wales.
It is not as yet known to the painters, but is greatly worth their attention; I have had it tried both in water and oil, in both which it makes a very fine colour.
This earth, by some experiments made on it, is found to be very inflammable, when prepared in a particular manner; I cannot say the experiment succeeded with me, but as it succeeded with several curious gentlemen of great veracity, I cannot omit giving it a place in my history; the first discovery of the inflammable property of this earth, was made by a Derbyshire gentleman, greatly esteemed for his knowledge, who published it in the Gentleman’s-magazine, for 1751, p. 70. and for February, 1752, p. 82. The account is as follows, “Having powdered and mixed this ochre with linseed oil, in order to grind for paint, I left it in a heap, and returning in about three quarters of an hour, found it rolling about in a gentle flame; the smoak and smell made it impossible to endure being near it. A second time I mixed about the same quantity, i. e. one pound and a half, to try if it would operate as before; it lay three quarters of an hour, and it felt quite cold; but a smoak ascending from a lump the bigness of a pea, I broke it, and in half an minute the whole was on fire, it did not flame till stirred, and then burnt with violence till the oil was consumed.”
By other experiments made at London, this earth, being lightly mixed with linseed oil, kindled in a little more than an hour and a half. It did not flame, but burnt with intense heat for more than three hours, till all the oil was consumed, and then it remained to appearance hardly diminished in weight, or otherwise altered in form or colour: when stirred, it emitted a quick kind of luminous vapour like bruised gunpowder. Upon mixing of it a second time, it fired again, tho’ after much longer trying; but on trying it a third time, it did not fire.
This earth, says the author, was got in a lead mine in the Peak of Derbyshire, about ten fathom below the earth’s surface; it is there further said, that it lies very deep in the earth, and that there are strata of it, from one inch, to ten or twelve inches thick, especially at Parwick, which is four miles north west from Ashborn, and at Elton, which is eight miles north west from Ashborn; that it is used in Derbyshire as paint, particularly to mix with other colours, to make them dry (where the colour will admit of such a mixture) as chocolate colour, mahogony colour, or other colours for priming, &c.
pp. 103–106
SECT. V. The Blue Ochres.
MEMB. I.
Alcaline Ochres.
I. Ochra friabilis cærulea.
THIS is quite a pure earthy ochre, of a fine pale blue or sky colour, of an even, regular, and compact texture, friable, or easily broken, and light, of a slight dusty surface, and colours the hands; it adheres to the tongue, melts readily in the mouth, has a disagreeable taste, and is pure; and very slowly breaks or moulders in water.
This ochre is found in very small roundish lumps, of the size of turnip seeds, mixed with a very dusky green coloured, loose, harsh, earth.
In the fire it acquires a dark brown colour.
That great naturalist, the late Sir Hans Sloane, Baronet, who presented me with this earth, informed me, he had received it by the name of blue earth from Ireland.
It would prove a fine and valuable colour in painting, could it be procured in any quantity.
I do not find any author mentions this species of blue ochre: indeed Kentm. Nom. Foss. p. 16, et 17. exhibits the following kinds, which very probably are of this species, viz. 1. Cæruleum pulcherrimum ultramarinum seu Cyprium in terra cinerea, simile cæruleo factitio optimo; 2. Cæruleum nativum insigne glebosum Schneebergense, intus concavum, quod ex terra candida fabulosa effoditur; and 3. Cæruleum nativum copiose adhærens terræ duræ cinereæ tenui; and Plot’s Nat. Hist. Oxfordshire. p. 57. exhibits a kind like Kentman’s second sort; he calls it a sort of cæruleum or native blue, found in very good plenty in marl at Blund’s Court, coating the small cavities of the earth. Wallerius also exhibits a variety of the Ochra cupri cærulea or Lapis Armenus, which he synonims Cæruleum montanum terreum, and describes it to be earthy, and not of a very compact or close texture, which perhaps may also belong to this species.
I cannot here omit taking notice of a very extraordinary earth, mentioned by Kentm. (an author of credit) Ibid. p. 1. Nº. 9. and p. 16. Nº. 3. he calls it Cæruleum Patavinum or Paduan blue, and says the clods of this earth are found in the fields, and when broken, contain in them an exceeding fine friable white earth, which in a short time turns blue, only by being exposed to the air.
Imperatus Nat. Hist. l. v. c. 44. likewise mentions this Paduan earth from Centomani; and tho’ he says it is not known to him, yet he gives credit to the account.
II. Ochra cærulea Lapis Armenus dicta.
Lapis Armenus. Hill’s Theophr. p. 100. Diosc. l. v. c. 65, et 66. Plin. Hist. Nat. l. xxxv. c. 6. Galen. l. ix. Simpl. Avicenna l. ii. tract. 2. c. 418. Mesues l. ii. de Simpl. Med. Purgan. c. 13. Agricola de Nat. Foss. l. iii. c. 19, 20, et 21. Aldrov. Mus. Met. p. 351. Cæsalp. p. 163. Calceol. Mus. p. 468. Schwenckf. Cat. Fos. Siles. p. 366. Imperat. Hist. Nat. l. iv. c. 6. et 23. Boet, de Boot, p. 293. Worm. Mus. p. 66. Grew’s Mus. Reg. Soc. p. 316. Bauschii Sched. de Cæruleo, &c. Woodw. Meth. Foss. p. 3. Nº. 9. et Cat. A. a. 51, et 52. et l. 26, 27, 28, et 29. Valent. Aurifod. Med. p. 42. Dale’s Pharm. p. 45. Nº. 2. Mercat. Met. Vat. p. 71, et 75. Mus. Richt. p. 216.
Azutum s. Cæruleum fossile. Merret’s Pin. Rer. Nat Brit. p. 218.
Ochra cupri cærulea, Bergblau. Linnæus’s Syst. Nat. p. 205. Nº. 3.
Cæruleum montanum, Bergblau. Cramer’s Ars docim. § 366.
Cuprum solutum vel corrosum, præcipitatum cæruleum, Cæruleum montanum, Ochra cupri cærulea, Chrysocolla nonnullorum authorum. Wallerius’s Mineral. Spec. 270.
Ochra cærulea friabilis, quæ Lapis Armenus. Azuthum. Hill’s Hist. Foss. p. 64. Nº. 1.
This is of an elegant bright or clear blue colour, sometimes of a deeper, sometimes of a paler blue, and also sometimes with a greenish cast, generally of a loose porous texture; tho’ it is also met with, but rarely, of a firm, compact, and regular texture; it is always of a stoney consistence, yet not hard, but breaks very easily between the fingers, and is as easily scraped with a knife; generally very light, of a pretty even and not dusty surface, nor does it colour the hands; it adheres slightly to the tongue, melts slowly in the mouth, is of a disagreeable taste, and difficultly breaks or moulders in water.
Burnt, it loses all its colour, becomes friable, and has a metallic slag-like appearance.
This kind is always found in and near copper mines, in most parts of the world. Authors recount its being found in most countries of Europe, in Italy, Hungary, Transylvania, Poland, Thuringia, Saxony, Bohemia, Silesia, and Spain.
In England we find it also in our copper mines; Dr. Woodward collected it on Wenskill hill, near Settle, as also at Malham in Yorkshire, (from whence I have likewise received it) in Cheshire, and in Derbyshire.
These ochres are often in reality good copper ores; the Lapis Armenus Doctor Woodward collected in Cheshire and Derbyshire, he informs us, yielded near half copper, and those from Yorkshire yielded one third and two thirds of that metal.
It is a very valuable and fine colour for painters.
In medicine, says Dr. Grew, unwashed, it works by vomit, and washed, by stool; it is highly celebrated by some, not only for its innocent, and most easy, but also most effectual operation, in such diseases as are supposed to depend on melancholy.
The confusion among authors relating to this substance, with the next to be described, and also with the Chrysocolla, or green ochre, hereafter to be described, is very easy to be reconciled, by considering, that as this ochre, which has also obtained the various names of Cæruleum æris, Cæruleum montanum, Cyaneum or Cæruleum metallicum, Terre bleue, Bergblau, and Berg l’asur; the next, which has also obtained the same names, without any distinction; and the Chrysocolla, are all generally found blended in masses together, they all owing their colours probably to an admixture of copper, and, as has been already observed, very often proving very rich copper ores; this circumstance has been the cause of its being so variously described, each author describing it according to the specimen he had then by him, without consulting any farther the nature of the substances themselves.
III. Ochra ponderosa elegantissime cærulea.
Cæruleum montanum lapideum. Wallerius’s Mineral. Spec. 270. Variet. 2.
An Ochra Cupri germinans cærulea, Kupfer blumen. Linnæus’s Syst. Nat. p. 205. Nº. 4?
This is a very ponderous ochre, of an elegant bright mazarine blue colour, of a fine glossy talc-like appearance, sometimes of a solid, compact, regular texture, but most generally of a fibrose or plated texture; it is not hard, but breaks easily between the fingers, and scrapes with a knife, of a harsh, rough surface, and colours the hands very slightly; it does not adhere to the tongue, does not melt freely in the mouth, is pure, but of very a disagreeable taste; and does not break or moulder away in water.
Burnt, it becomes friable, loses all its colour, and acquires a dusky metallic appearance.
This is also found in copper mines, and is in reality a very rich copper ore, it yielding sometimes ½, sometimes ¾ copper.
It is found in the copper mines in many parts of Germany. I have received exceeding fine specimens of it from the mountains of Medenbeck, in Vallachia; and I have also seen veins of it intermixed with some English Lapis Armenus.
It is very probable this kind of ochre is found in great plenty in China, for I am
I am positive the fine deep blue colour, so much used in the Chinese paintings, is this very substance.
It would make a most valuable colour for painters.
pp. 106–109
SECT. VI. The Green Ochres.
MEMB. I.
Alcaline Ochres.
I. Ochra viridis, Chrysocolla vel Viride montanum dicta.
TERRA viridis, Viride montanum s. nativum, Chrysocolla, Berg-grün, Steingrün, Schiefer-grün, Kupfer-grün, Terre verte. Kentm. Nom. Foss. p. 16. Schwenckfeldt Cat. Foss. Siles. p. 374. Hubner Lex. Nat. et Art. p. 248. Bauschius’s Sched. de Cæruleo et Chrysocolla, c. 12. p. 134. et seq. Grew’s Mus. Reg. Soc. 349. Valent. Aurifod. Med. p. 6. et 56. Wolckm. Siles. Subt. p. 250. Kundm. Prompt. p. 279. Nº. 19. Woodw. Meth. of Foss. p. 3. Nº. 8. et Cat. A. a. 50. Cat. I. a. 34. et Cat. L. a. 33. Mus. Richt. p. 54, 65, et seq. Cramer’s Ars Docimast. § 366. Bruckm. Epist. Itin. Cent. i. Ep. 2. et Ep. 76. p. 6. et Cent. ii. Ep. 54. p. 576. Nº. 1, 2, et 3.
Chrysocolla. Hill’s Theophr. p. 71. et p. 103. Diosc. l. v. c. 64. Vitruvius’s Architect. l. vii. c. 14. Plin. Hist. Nat. l. xxxiii. c. 5. Galen l. ix. Simpl. Averroes Simpl. c. 43. Avicen. l. ii. canon. tr. c. 704. Agricola de Nat. Foss. l. iii. c. 1, 19, et 20. Cæsalp. de Metall. l. ii. c. 63. Encelius de re Metall. l. i. c. 4. et l. ii. c. 21. Aldrov. Mus. Met. p. 348. Imperat. Hist. Nat. l. iv. c. 8. 31. et 32. Boet de Boot, c. 142. Worm. Mus. p. 128. Mercat. Met. Vat. p. 67. et 75.
Ochra Cupri viridis Berg-grün. Linnæus’s Syst. Nat. p. 205. Nº. 2.
Cuprum solutum vel corrosum, præcipitatum, viride. Ærugo nativa, Chrysocolla Agricolæ, Ochra Cupri viridis, Viride montanum. Wallerius’s Mineralogy, Spec. 269.
Ochra virescens. Hill’s Hist. Foss. p. 65. Nº. 2.
This ochre, which is found of different degrees of green, from the pale to the brightest green colour, is, as well as the blue ochres before described, a copper ore, generally very rich, and owes its production to that metal corroded and precipitated in the bowels of the earth.
It assumes various appearances, sometimes it is of a solid, compact, regular, texture, heavy, hard, so as not to be broken between the fingers, and of an even surface; sometimes quite of an earthy consistence, light, friable, and of a dusty surface; and sometimes is dry, and of a granulated structure.
In all these appearances it does not colour the hands, does not adhere to the tongue, does not melt in the mouth, is of a very nauseous taste, and does not break or moulder in water.
In the fire it loses all its colour, and generally becomes more friable.
It is always found in and near copper mines in most parts of the world; sometimes it is carried by the waters of the mines, which deposite it on the sides, and at the bottom of their adits, in form of a loose light powder; it is also found incrusting the ores of copper, and minerals accompanying them, and is also found in solid masses.
In England we find it in our copper mines in Cornwall, Yorkshire, Cumberland, and Derbyshire, &c. but not in any quantity; and Dr. Woodward collected the loose kind on the sides of the great copper vein at Goldscalp, in Cumberland, where it was brought and deposited by the waters, which continually trickled down the sides.
I am also informed, some quantity of this ochre has lately been found in the copper mines of Wicklow county, in Ireland.
It is found in great plenty in Saxony and Bohemia, at Goldberg, Kupferberg, Brausnitz, Hermanseiffen, Schatzlar, and Waltersdorff, in Silesia, and in many other parts of Germany; in the mountains of Medenbeck in Vallachia, in Poland, and in Sweden, but in the greatest quantity, and of the finest sort, in the kingdom of Hungary.
As the Berg-grün made in Hungary, and which is exported in great quantities to most parts of Europe, differs no otherwise from the native sort, than as the washed ochres do from those sent us in their native condition, I do not think it at all improper here to transcribe from Bruckman’s Epist. Itin. Cent. i. Ep. 76. the method of collecting and preparing this valuable paint, as observed by the author himself in 1724.
The Chrysocolla or Berg-grün, says that author, is collected at Neusohl, in the mountainous territory called Herrengrund, in Hungary; the waters of those mines abound with this substance; the miners, to collect it, turn and carry off these waters by numbers of wooden pipes, to great square wooden reservoirs, made of large planks, wherein the water deposites this green substance; when they have thus obtained a large quantity of the ochre, and that the reservoirs are incrusted with it to a good thickness, the water being turned off, they scrape off the Chrysocolla or green ochre from these vessels, then dry it, and divide it into three sorts; the first sort, which is the worst or common kind, is that taken out of the first or upper reservoir, wherein the water first falls; the second, or middle sort, is in like manner collected from the second reservoir; and the third sort, which is the finest and most valuable, they collect from the lower reservoir, or wherein the water flows last of all: These reservoirs are placed above each other, but communicate by means of inclining wooden pipes, so that the first is placed higher than the second, and the second higher than the third, and the water gradually flows from the uppermost to the lowest reservoir.
These ochres, thus collected, are afterwards exposed to a clear summer sunshine to dry, and are then put up for sale; the first, or worst sort, is impure, or gritty, and of a dusky green colour; the second sort is somewhat purer, of a middling colour, between the dark green of the first sort, and the bright green of the third or best sort; and the third sort is entirely fine, pure, and of a most beautiful bright green colour, and suffers no depurations or washings before it is used, as the other two sorts, which are again washed to free them from their heterogeneous parts.
At Richtergrund, about a mile from Neusohl, this ochre is also collected in the same manner, but not in so great quantities as at Neusohl. Dr. Bruckman further observes, that this ochre can only be collected from very rich veins of copper ore, as it in reality is only a Crocus veneris nativus, corroded by an acid, and thus destroyed or decompounded into a powder; for the miners have always observed, that where the ore is of a poor nature, no Chrysocolla or Berg-grün is ever to be found.
The Chrysocolla is greatly used, and esteemed by painters, as a valuable and elegant colour; Imperatus observes, that the walls, paintings, &c. of the Romans with this colour, which yet remain, are as lively and as fresh as if they were but newly painted.
In medicine it likewise has its uses; it purges and vomits when used internally, which is seldom; it is externally applied for the drying up of ulcers, and sores of all kinds; and Sennertus says, he used it with great success in his ointment for scorbutic ulcers of the legs.
The Chrysocolla of the ancients, so called for its use in soldering gold, and which name we now give to the Borax on the same account, are substances which resemble each other in no one thing but that property; however, the same name having been given to two such very different substances, has proved the cause of much confusion and error among authors; even the great and learned Dr. Woodward, misled by the name, in his Method of fossils, p. 25. Nº. 3. talking of the Tincal of the Persians, from which the Borax is made, says, this seems to be the Chrysocolla of the ancients: Agricola first hinted this ochre, or Berg-grün, to be the ancient Chrysocolla, and since his time, it has on that account been called by that name, and allowed to be so by the generality of authors, especially the German writers. If we consider the accounts of the ancients concerning their Chrysocolla, I cannot but think this ochre in all probability and reason to be the same substance; they describe it to be found loose and in form of sand, and of a fine green colour; of the colour of a leek, says Dioscorides; and Pliny expresses himself, Summa commendationis est, ut colorem herbæ segetis læte virentis quam simillime reddat. He further describes it, Humor in puteis per venas auri defluens, but that the best was found in copper mines, and was collected in June and July, from the waters in the said mines; and further, that it was thought to be only a rotten vein of ore, Ut plane intelligatur nihil aliud Chrysocolla quam vena putris, are his words; it was found also in silver and lead mines; to which, Agricola observes, that the ores of those other metals wherein it was found were undoubtedly also impregnated with copper, for that it is only the produce of copper. Not a more adequate description of the Berg-grün could have been given, than this description of Pliny’s of the Chrysocolla, viz. a corroded or destroyed copper ore, carried by the waters, and deposited by them in the mines, loose or in form of sand, of a fine green colour, and collected or prepared in the summer: but if the Berg-grün, has that property of soldering gold, either by itself or added to other substances, (which, tho’ not expressed by the ancient authors, I take to have been the case) must be left to future enquiries.
Hill, in his Theophrastus, p. 71. erroneously imagines the Chrysocolla of the ancients to be a sparry matter, of a beautiful green colour, found in copper mines in form of sand. In his Hist. of Foss. p. 580. he asserts, what he only hinted before, and on that account synonims the Chrysocolla of the ancients, Saburra crassior, hebes, læte virens, quæ Chrysocolla antiquorum. That gentleman, to enforce his opinion, observes, that this green sparry matter is frequently found in form of sand: that it possesses the qualities of the Chrysocolla of the ancients, that it proved a violent emetic to a dog he gave it to, and, to crown all, roundly asserts, he has tried it in soldering metals, and has found it to serve that purpose better than Borax: I am sorry to criticise on any ones works, but if we consider the nature of spar, or sparry matter, I am certain it will be found to be a very unfit substance to solder any metal, and of consequence, I greatly doubt the veracity of that gentleman’s assertion. The other properties, of being green, in form of sand, and found in copper mines, are all properties equally common to the Berg-grün, as well as to his green spar; and the emetic quality of his green spar is likewise a property common not only to the Berg-grün, but also to all substances whatever, which are strongly impregnated with cupreous particles.