Parting of Gold

Reti, Ladislao. Parting of gold and silver with nitric acid in a page of the Codex Atlanticus of Leonardo da Vinci. Isis 56, no. 3 (Sep 1965) 307-319. 

Of bronze (aeris) 3 parts, of silver 1 part, melt together and add orpiment, not roasted, 3 parts. When strongly heated let it cool and put in a pan and cover with clay and roast until cerusa is made. Take it out and melt and you will find silver. If too much roasted, electrum will be made, to which if 1 part of gold is added it will make the best gold. 

The parting of gold and silver by means of sulphur is first clearly described by Theophilus.07... 

By dissolving in warm mercury, pure red hot gold in the proportion of one part of gold to seven parts of distilled mercury. See Secreta Alchemice of St. Thomas Aquinas. 

Quartering.—This designation is applied to the parting with nitric acid mentioned above, although it is also employed to describe the sulphuric-acid process. Usually, the gold-silver alloy is made to contain 2 parts of gold to 5 parts of silver. It is granulated, and boiled with nitric acid. The silver solution produced is either worked up into lunar caustic, or precipitated as chloride by addition of sodium chloride, and then reduced to metal. 

The Scale of the Stone The ash is the ferment of the gold, and the gold is its water. Body and ferment shall afterwards be a clean powder dissolve them both in water before they are united. The ferment shall be the fourth part of our ore, i.e., four parts of ore and one part of ferment. But Rhasis speaks of 19 parts, another of 3 parts of gold and 7 of water, because the ferment is manifold, so also is the process. Sometimes the ferment is the Stone, and sometimes gold and silver, alone or both together. 

PANDALITIUM, PANERITIUM, PASSA, VERMIS — An Abscess at the End of the Fingers. PARS CUM PARTE — A Composition of Equal Parts of Gold and Silver. 

QUARTATIO — is a separation of Gold and Silver it is the alloying of one part of Gold, with three of Silver. 

Available forms Ingots sheet wire tubing powder leaf alloys with copper or other metals, the gold content being expressed in carats (the number of parts of gold in 24 parts of alloy). Single crystals and aqueous colloidal suspensions. Leaf may be made in near-colloidal thickness one troy ounce covers 68 sq ft at 0.0001 inch thickness. 

One part of antimony in one thousand parte of gold i.s suffleient to destroy the working properties of It. From this peouliar action the ancients gavo it the name regulus or little kiug. ... 

The tendency of mercury to combine with gold and silver is made use of in extracting these metals from their ores. An amalgam of 1 part of gold, and 8 of mercury, is used in gilding brass. 

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