Elements of the Art of Assaying Metals |
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Page 8
... Veffels closely fhut , fuftain a moderate melting Fire , without any Alteration ; when the Heat is in- creased , they are put in Fufion ; and then the first black kind of them turns into a clear black Glafs ... Veffel , and then The ART of.
... Veffels closely fhut , fuftain a moderate melting Fire , without any Alteration ; when the Heat is in- creased , they are put in Fufion ; and then the first black kind of them turns into a clear black Glafs ... Veffel , and then The ART of.
Page 14
... Veffels , and come to the Operations them- felves , it is proper for us to fhew the Nature of those Bodies , which are to be contained in thefe Veffels , directed and applied by these Inftruments ... Veffel , where it turns 14 The ART of.
... Veffels , and come to the Operations them- felves , it is proper for us to fhew the Nature of those Bodies , which are to be contained in thefe Veffels , directed and applied by these Inftruments ... Veffel , where it turns 14 The ART of.
Page 15
Johann Andreas Cramer Cromwell Mortimer. to the Side of the Veffel , where it turns into Drofs cal- led Litbarge ... Veffels turn red , the Tin immediately rifes above the Lead , like little whitish dufty Hillocks ; fo that one unfkill ...
Johann Andreas Cramer Cromwell Mortimer. to the Side of the Veffel , where it turns into Drofs cal- led Litbarge ... Veffels turn red , the Tin immediately rifes above the Lead , like little whitish dufty Hillocks ; fo that one unfkill ...
Page 16
... Veffel having a wooden Cover , or fome other Veffel in which a Fluid may be very ftrongly fhaken , without however any danger of its running out . But let the Sides of the Veffel be well rubbed with Chalk or Wax ; then let it be ...
... Veffel having a wooden Cover , or fome other Veffel in which a Fluid may be very ftrongly fhaken , without however any danger of its running out . But let the Sides of the Veffel be well rubbed with Chalk or Wax ; then let it be ...
Page 22
... Veffel , able to refift the greatest Fire ; and if finally , the Veffel being well clofed with only a fmall Aperture left to it , is expofed for fix or eight Hours , first to a moderate Fire encreafed at laft to the higheft Degree , fo ...
... Veffel , able to refift the greatest Fire ; and if finally , the Veffel being well clofed with only a fmall Aperture left to it , is expofed for fix or eight Hours , first to a moderate Fire encreafed at laft to the higheft Degree , fo ...
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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...