Gold, very pure

X-ray diffraction confirms linear coordination in Au(PPh3)(C=CC6F5) and Au(H2NCHMe2)(C=CPh) with the short Au-C bonds (1.935-1.99 A) expected for bonds to sp hybridized carbon. Decomposition of these compounds in the vapour above 150°C is a potential route to very pure gold films [162],... 

Philalethes says, in A Brief Guide to the Celestial Ruby. "The Philosopher s Stone is a certain heavenly, spiritual, penetrative, and fixed substance, which brings all metals to the perfection of gold or silver (according to the quality of the Medicine), and that by natural methods, which yet in their effects transcend Nature.. . Know then that it is called a stone, not because it is like a stone, but only because, by virtue of its fixed nature, it resists the action of fire as successfully as any stone. In species it is gold, more pure than the purest it is fixed and incombustible like a stone, but its appearance is that of very fine powder, impalpable to the touch, sweet to the taste, fragrant to the smell, in potency a most penetrative spirit, apparently dry and yet unctuous, and easily capable of tinging a plate of metal. If we say that its nature is spiritual, it would be no more than the truth if we described it as corporeal, the expression would be equally correct."... 

We believe that the problems connected to the metastability/instability of the networks of steps deserve further experimental investigation, as well. If e is positive, as we think should be the case for gold and platinum crystals, one should be able, starting from the metastable network of steps, to observe a nucleation of arrays of parallel steps connected under a ridge. Probably this could be observed in practice, e.g. in STM experiments, only for sufficiently high temperatures and in very pure samples. 

Sucrose is regarded as the gold standard for a sweet taste. It is manufactured from cane or beet and available in crystalline or liquid form. Sucrose is a disaccharide with a molecular weight of 342.31. It is available in a very pure state and in a variety of physical forms. 

The matter of the Great Work was Gold and Silver united to Mercury and prepared in a special manner. Gold was chosen for its abundance of Sulphur, Silver as containing a very pure Mercury, as for quicksilver, it represented the Salt, mean for uniting both Sulphur and Mercury. 

Electrolysis is used in a wide variety of ways. Three examples follow (1) Electrolysis cells are used to produce very active elements in their elemental form. The aluminum industry is based on the electrolytic reduction of aluminum oxide, for example. (2) Electrolysis may be used to electroplate objects. A thin layer of metal, such as silver, can be deposited on other metals, such as steel, by electrodeposition (Eig. 14-2). (3) Electrolysis is also used to purify metals, such as copper. Copper is thus made suitable to conduct electricity. The anode is made out of the impure material the cathode is made from a thin piece of pure copper. Under carefully controlled conditions, copper goes into solution at the anode, but less active metals, notably silver and gold, fall to the bottom of the container. The copper ion deposits on the cathode, but more active metals stay in solution. Thus very pure copper is produced. The pure copper turns out to be less expensive than the impure copper, which is not too surprising when you think about it. (Which would you expect to be more expensive, pure copper or a copper-silver-gold mixture )... 

Pure copper is deposited on the cathode, the anode being gradually dissolved. Impurities in the copper, such as iron, zinc, nickel, c., of which the sulphates are soluble, are allowed to accumulate in the solution until their quantity renders the liquor inconvenient to deal with. At this stage the copper in the liquor is precipitated with metallic iron and fresh solution substituted. Other metals present, such as platinum, gold, silver, lead, and arsenic, form a fine mud in the bath, and this mud is afterwards treated for recovery of the precious metals. Thus, by this scientific method, not only is copper obtained in a very pure state, but the gold, silver, and platinum also can be extracted profitably. 

The very pure platinum obtained after ignition is free of all the other platinum metals, gold and the heavy base metals. If the Pt still contains a few tenths or hundredths of a percent of Ir, the purification process can be repeated. 

But we now wish to proceed to the Oleum Antimonii and its Power, and show how this oil may also help the diseased and imperfect metallic bodies. Take in the Name of God, very pure refined gold, as much as you want and think will suffice. Dissolve it in a rectified Wine, prepared the way one usually makes Aquam Vitae. And after the gold has become dissolved, let it digest for a month. Then put it into a Balneum, and distil off the spiritum vini very slowly and gently. Repeat this several times, as long and as often until you see that your gold remains behind in fundo as a sap. And such is the manner and opinion of several of the ancients on how this oil may also help the diseased and imperfect metallic bodies. 

Weidhaas and Lang (2004) carried out the measurements on trace elements on surface by Rutherford backscattering using nitrogen ions. They found that the detection limit for heavy elements e.g., gold in silicon, a surface sensitivity of 10 atoms cm is reached while for medium elements, e.g.. As, Cr, and Fe, the detection limit is 10 atoms cm . HIBS has been used by Banks et al. (1998) for measuring extremely low levels of surface contamination on very pure substrates, such as Si wafers used in the manufacture of integrated circuits. 

Answer by author Very pure copper has a substantially different thermoelectric power from that of thermocouple copper below about 30 K. Minor changes in cold-working will not seriously affect the gold-cobalt wire since it is already substantially reduced in cross-section by cold-drawing (about 10 reduction). 

During the electrolytic step of copper production an anode slime is obtained, containing the noble metals of the ore. They are extracted by a compHcated process. Raw silver is obtained by melting, and is used as a new anode material. In an electrolytic process with nitric acid as electrolyte silver dissolves from the anode while gold and platinum form a new anode sHme. Silver is precipitated from the electrolyte as silver chloride. This is melted with soda and saltpeter at 1000°C. The molten silver is cast into bars and remelted in vacuum to yield very pure, gas-free silver. 

Electrolysis is also used to purify some metals. For example, copper for electrical use, which must be very pure, is purified by electrolysis. Slabs of impure copper serve as anodes, and pure copper sheets serve as cathodes the electrolyte bath is copper(II) sulfate, CUSO4 (Figure 20.24). During the electrolysis, copperfll) ions leave the anode slabs and plate out on the cathode sheets. Less reactive metals, such as gold, silver, and platinum, that were present in the impure copper form a valuable mud that collects on the bottom of the electrolytic cell. Metals more reactive than copper remain as ions in the electrolytic bath. After about a month in the electrolytic cell, the pure copper cathodes are much enlarged and are removed from the cell bath. 

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