VITRIOL. 



tliat he there faw two fpriiigs, called tlie old and new Ziment, 

 which turned iron into copper. The iron in this cafe is 

 taken up by the water, and remains fufpendcd in it, in the 

 place of the copper : fo that this tranfmutation is notliing 

 but a change of place ; and as the copper is precipitated by 

 the iron, fo the iron might be precipitated by pot-afh, or 

 any otlier fubllance which has a greater affinity with the 

 acid of vitriol than iron has. 



The caufe of the impregnation of tliefe copper waters 

 in Germany is not difficult to be explained. Moll copper- 

 ores contain fulphur, and when the fulphur is in any degree 

 decorapofed, its acid unites itfelf to the copper, and forms 

 blue vitriol, which is the fubllance witli which the waters 

 iffuing from the copper-mines are impregnated. The copper 

 contained in thefe waters has been for fome centuries col- 

 lefted in Germany, by putting old iron into pits filled with 

 the coppery water ; and thus the iron is diffolvcd, and the 

 copper is precipitated, and being raked out in the form of 

 mud, it is afterwards melted into very fine copper. The 

 quantity of copper procured by an hundred tons of iron 

 amounts fometimes to ninety tons, and feldom to lefs than 

 eighty -four. Of late years fome fuccefsful attempts ot 

 this kind have been made in England and Ireland. See 



COPPEK. 



In the Ifle of Angkfey, near Paris mountain, which 

 abounds in copper ore, the water in which the roailed ore 

 is waflied is fo llrongly impregnated with copper, that they 

 have found it ufeful to adopt tlie German method of pre- 

 cipitating it by means of old iron, and they have obtained in 

 one year near a hundred tons of copper, precipitated from 

 this water. The water, after the copper has been pre- 

 cipitated by means of iron, is at prefent thrown away ; 

 whereas, by ev.aporation, it would yield green vitriol ; and 

 as above a hundred tons of iron mud be employed in ob- 

 taining the forementioned quantity of copper, Dr. Watfon 

 fuggefts, whether a manufadlory of green vitriol might not 

 be eilabliflied at this and at all other places where copper is 

 obtained by precipitation. One hundred tons of iron 

 would yield, at the lead, two hundred tons of vitriol, which, 

 at the low price of 3/. per ton, would defray the expence of 

 extradtnig it ; more efpecially as the watery folution might 

 be evaporated bv a proper application of part of that heat, 

 which is now loll in all the great fmelting houfes. 



The greatelt part of the blue vitriol, now met with in the 

 (hops, is prepared in England, by artificially combining 

 copper with its fulphur or its acid. The method ot making 

 the preparation by the glafs-makers is this : Take httle thin 

 pieces of brafs, and lay them ilratum fuper ftratum in a 

 crucible, with powder of brimRone. When the vefLl is 

 full, fet it luted and covered in an open wind-furnace, with 

 burning coals over it, and let it ftand two hours ; then let 

 the furnace cool of itfelf, and take out the crucible, the 

 mafs within will be of an obfcure blackifli-purple ; powder 

 it and fift it fine, and then- mixing with every pound of it 

 fix ounces of powdered brimiloiie, take a round vefFcl of 

 earth, that will bear the fire, place it upon iron bars fet 

 acrofs in an open wind-furnace, fill it with coals, and then 

 put in the powder ; keep it burning and ftirring about till 

 all the brimllone is burnt up ; then take out the pan, and 

 powder the calcined mals again ; fift it fine, and proceed 

 with it thrice as before ; tlie laft time let it Hand on the fire 

 till it becomes red. Put a pound of this calcined cupper 

 into a glafs body, with fix pints of water ; evaporate two 

 pints or thereabout in a fand heat ; the water is tlien of a 

 fine blue, and mull be poiireJ off clear ; then filtrate it. 

 Evaporate the water from tlie remaining ftdiment of copper 

 left in the glafs, and with new fulphur calcine it ag<iin and 



ag.ain ; repeat this five or fix times, and extraA the blue 

 tinfture with water as before ; filtrate aU the waters, and 

 put them together. Evaporate all to a fifth part, or there- 

 abouts, and let it in a cool place, and fine pointed cryftals 

 will be formed, refembling emeralds ; feparatc thefe cry Hals 

 and evaporate the water again, till all the cryftals be pro- 

 cured. Then put a pound of them into a glafs retort, well 

 luted, and fitted to a capacious receiver ; let the joints be 

 well clofed, and make a modenite fire for four hours ; then 

 make it violent for twenty hours, or till no more white fumes 

 arife. The next day open the receiver, and leparate the 

 liquor into a glafs, where it muft be kept carefully fealed 

 up. Neri's Art of Glafs, p. 50. 



Very great things are to be done in the glafs art by means 

 of this liquor ; the remainder in the retort expofed to the 

 air for a few days, will acquire a blue colour, and this, 

 mixed with zaff"cr, will give glafs a fine fea-green. The 

 vitriol of copper is of an elegant fapphire blue colour ; 

 hard, compaft, and femitranfparent ; when perfectly cryilal- 

 hzcd, of a flattidi, rhomboidal decahedral figure ; in talle 

 extremely nanfeous, fl;yptic, and acrid. Expofed to a 

 gentle heat, it firil turns white, and then of a ycllowi(h-red 

 or orange colour ; on increafing the fu-e, it parts, difficultly, 

 with its acid, and changes at length to a very dark red calx, 

 reducible, by fufion with inflammable fluxes, into copper. 



Some writers hold vitriol to be the root or matrix of 

 copper ; becaufe, in the copper-mines, they never dig 

 deeper than the glebe, out of which the vitriol is drawn. 

 For the ufe of blue vitriol in medicine, &c. fee Vitriol, in 

 AIiYilcine. 



The luhke •vilriol, or vitriol of zinc, is found native in the 

 mines of Godar, fometimes in tranfparent pieces, more 

 commonly in white efflorefcences ; which are diflolved in 

 water, and cryilalUzed into large irregular mafles, fome- 

 what refembling fine fugar ; it is alfo found dilfolvcd in 

 mineral waters, and generally with fome proportion to the 

 vitriol of iron and copper : it is in talle fweetifli, naufeous, 

 and ftyptic. 



It has been difputed, whether white vitriol is any thing 

 elfe than green vitriol calcined. But it feems that white 

 vitriol is of a quite different fpecies from either the green or 

 the blue vitriols. Geoffroy, Mat. Med. torn. i. p. 124. 



In the condition in which white vitriol is ufually bought, 

 it contains fomewhat both of copper and iron ; but being 

 purified by folution, filtration, and cryllallization, it is freed 

 from both thefe metals, and appears to be a native vitriol 

 fur generis. See Cramer, Elem. Art. Docim. vol. i. p. 302. 

 ed. 2. Med. Efl". Edinb. Abr. vol. ii. p. 472. 



If tour ounces ot alum be put in concodlion with two 

 parts of cadmia tolfilis pulverized, the earth of the alum 

 precipitates, and its acid takes hold of the earth of zinc, fo 

 that a true white vitriol is the rtlult. 



This vitriol being precipitated by an alkaline ley, and 

 dried, after its falts are feparated in water, and then mixed 

 with charcoal-dull, will give zinc. 



The fame thing happens in mixing vitriol of iron with 

 two or three parts of lapis calaminaris ; but the operation 

 is eafier with alum and vitriol of copper. Marggraaf, in 

 Mem. de I'Acad. de B rliii, 1746. 



The white vitriol requires little more than twice its wciglit 

 of water to didblve it in tiie temperature of 60" ; its fpecific 

 gravity is about 2.000. It mixes uniformly with vitriolic 

 neutral falts, but precipitates nitrous or marine felenites Irom 

 their lolutions, which afcertains its acid principle ; it is 

 itfelf precipitated whitilh by alkalies and earths, but not by- 

 iron, copper, or zinc, which fufficiently indicates its bafis : 

 if it contains any other metallic principle, tills may be pre- 

 cipitated 



