Elements of the Art of Assaying Metals |
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Page 56
... Inch thick with dry Afhes , put upon it the Mortar con- taining the Coppel already prepared , fo that the lef fer Bafis of it be underneath ; prefs it against the fmall Board : the Coppel will then eafily quit its Mould Let next the ...
... Inch thick with dry Afhes , put upon it the Mortar con- taining the Coppel already prepared , fo that the lef fer Bafis of it be underneath ; prefs it against the fmall Board : the Coppel will then eafily quit its Mould Let next the ...
Page 59
... inch thick . When preffed , add upon them fome other . Alhes , to be preffed in the fame manner ; till the earthen Veffel be almoft quite full : Remove the fu- perfluous Ashes with an Iron Rule . ( 5. ) Let the In- equalities remaining ...
... inch thick . When preffed , add upon them fome other . Alhes , to be preffed in the fame manner ; till the earthen Veffel be almoft quite full : Remove the fu- perfluous Ashes with an Iron Rule . ( 5. ) Let the In- equalities remaining ...
Page 63
... Inches high , fix or eight Inches long , and four or fix Inches broad . The Segments cut off at the Bafis for the leffer Holes , must be so high as that at least the small Veffels put under them , may not be tainted by Coals and Ashes ...
... Inches high , fix or eight Inches long , and four or fix Inches broad . The Segments cut off at the Bafis for the leffer Holes , must be so high as that at least the small Veffels put under them , may not be tainted by Coals and Ashes ...
Page 64
... Inch the Sides and hinder - Part of the Muffle ( N ° 2. and 3 ) , that the latter may with the greater Security stand upon it as a Bafis . Then , with your Hand wet , rub the Muffle thus made all over ; that the fmall Chinks , perhaps ...
... Inch the Sides and hinder - Part of the Muffle ( N ° 2. and 3 ) , that the latter may with the greater Security stand upon it as a Bafis . Then , with your Hand wet , rub the Muffle thus made all over ; that the fmall Chinks , perhaps ...
Page 68
... Inches high , with a very narrow Orifice , hardly half an Inch wide ; left the Matter therein contained , being in a violent Ebullition , fhould rife over the Mouth of the Veffel , or at leaft Part of it be thrown out in fmall Drops ...
... Inches high , with a very narrow Orifice , hardly half an Inch wide ; left the Matter therein contained , being in a violent Ebullition , fhould rife over the Mouth of the Veffel , or at leaft Part of it be thrown out in fmall Drops ...
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Common terms and phrases
Acid alfo alkaline almoft Antimony APPARATUS Aqua Fortis Arfenick becauſe Befides Bifmuth Body Borax Bottom brittle Cafe calcined Calx Caput Mortuum Centners Cinnabar clofe cloſe Coals Colour commonly confifts confumed contains Copper Crucible Cucurbite diffipated diffolved docimaftical eafily Earth efpecially expofed faid faline fame Manner fecond feparated feveral fhall fhould Fire firft firſt fixt Flux fmall fmall Quantity folid fome fometimes foon foregoing ftill ftir ftrong fuch fufficient fufible Fufion Furnace Glaffes Glafs Gold Hole Inches increaſe Inftance intirely Iron itfelf laft Lead leaft lefs likewife Litharge Lute Mafs melted Mercury metallick Metals Minerals mixt Mixture moft moſt Muffle muft muſt neceffary Nitre obferve Operation Phlogifton Plat Powder precipitated Proc Procefs pure Pyrites red-hot reduced refractory reft Regulus remaining Roafting Salt Scholion Scoria Semi-Metals Silver ſmall Stones Sublimation Sulphur Teft thefe theſe thofe thoſe Ufe and Reafons unleſs uſe Veffel Vitriol Water Weight yellow Zink
Popular passages
Page xii - Lipsiae, 1734, in three tomes, in folio : in the second and third tomes of which he has given the best accounts, not only of the methods and newest improvements in metallic works in all places beyond the seas, but also of those in England and our colonies in America, with draughts of the furnaces and instruments employed. It is to be wished we had extracts of this work in English.
Page xiii - Rara Avis in Terris : or the Compleat Miner, in two Books ; the first containing, the Liberties, Laws and Customs of the Lead-Mines, within the Wapentake of Wirksworth in Derbyshire ; in fifty-nine Articles, being all that ever was made.
Page 98 - Plate (z), one Inch and a half long-, and of fuch Breadth and Thicknefs, as that it may freely move up and down, and yet not have too much play within the Hole. Moreover, let this Plate have a fmall Plook at each Extremity. 266. And as fuch a Balance is very ticklifh, and will hardly {hand flill in the open Air, and...
Page 75 - And that thisr being put on the Aperture (d) of the Furnace, may not be eafily thrown down, let an Iron Plate be rivetted to the right and left upper Edge of the Furnace (cc), and be turned down towards the Infide,' fo as to make a Furrow open before and behind, into which the lateral Edges of the Cover may enter and be fattened, and at Pleafure be moved backwards and forwards, whenever it muft be put on, or removed.
Page 247 - ... mercury is finally to be squeezed through thin leather and the solid amalgam distilled in a glass retort on a sand bath. He mentions the danger of precious metal passing into the receiver with the mercury when the fire is too strong. He adds the following caution (following Mortimer's translation): "If, for want of an apparatus for scorification and coppelling, you have a Mind to indicate by this method, the Quantity of Silver contained in the Body washed ; in this case the whole Amalgama must...
Page 49 - great many fluxes with the above-mentioned salts and with the reductive ones ; nay, 1 some use as many different fluxes as there are different ores and metals ; all which, however, ' we think needless to describe.
Page xiii - Silver that fhall be extracted by the Art of Melting and Refining of Metals, and otherwife improving of them and their Ores, be from henceforth imployed for no other Ufe but the Increafe of Monies ; that it be carried to the Tower of London, where the Owner fhall receive the full Value.
Page xiii - William and Mary, ch. 30. An Act to repeal the statute made in the fifth year of King Henry IV. against multiplying gold and silver. The Whole Act 5 William and Mary, ch. 6. An Act to prevent disputes and controversies concerning Royal Mines. The Whole Act 55 George III, ch.
Page 247 - Amalgama must be distilled through the Retort; because Part of the Silver and gold gets through the Leather: Nay, there remains nothing at all of the Silver or Gold within the Leather, if you use too great a Quantity of Mercury, to extract a small Quantity of these Metals : unless the Mercury be saturated with them, by a like previous Process; and even then, you may be easily deceived as to the Quantity and Quality of the Metal.
Page 242 - ... use of iron filings is mentioned by Mitchell and by Percy, both of whom refer to still earlier work. In fact, this seems to have been one of the earliest forms in which iron was used for assay purposes. In Cramer's work on assaying (Mortimer's translation, 2d ed., 1764) one section is devoted to " Precipitation by Iron and Lead of Silver out of a Mixture containing a great Deal of Sulphur...