Parting of Gold and Silver with Nitric Acid in a Page of the Codex Atlanticus of Leonardo da Vinci
Parting of Gold and Silver with Nitric Acid in a Page of the Codex Atlanticus of Leonardo da Vinci
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列奥纳多·达·芬奇《大西洋手抄本》的一页中用硝酸分离金和银的过程
作者：
L. Reti
自然界中绝大多数的金都含有银，正如银矿石通常含金一样。当贵金属精矿被加工时，就形成了混合合金，如古代的银金矿。通常，出于技术原因以及出于经济原因，分离是期望的。据我们所知，古代的这种分离过程都是以所谓的胶结作用为基础的。在这个过程中，合金薄片与由盐、砖屑、硫酸、明矾和其他材料组成的混合物层交替，然后一起加热。银被转化为氯化物，随后可以通过多种方式将其分离。另一种分开的方法首次出现在西奥菲勒斯的作品中，1这是一种基于与硫融合的过程。虽然西奥菲勒斯生活在1120年左右，但他所描述的过程可能要古老得多。因此，硝酸的使用是一个相对较新的发展，尽管它起源于何时何地尚未确定。我们第一次听说酸本身是在伪Geber的著作中，可能属于13世纪后期。很可能酸已经被用于炼金术实验相当长的时间，而没有被用于实际目的。贝克曼提到了一个古老的传统，即硝酸最初是由威尼斯的一些德国人在贵金属的分离中使用的。
M ,f OST of the gold in nature contains silver, just as silver ores are usually auriferous. When the precious metal concentrates are worked up, mixed alloys such as the electrum of the ancient world are formed. Generally, for technical reasons as well as for the sake of economy, separation is desirable. As far as is known, the ancient processes for this separation are all based on so-called -cementation. In this process thin sheets of the alloy were alternated with layers of a mixture consisting of salt, brickdust, vitriol, alum, and other materials, and then heated together. The silver was converted into chloride which could subsequently be separated in a number of ways. Another method of parting appears for the first time in the works of Theophilus,1 a process based on a fusion with sulphur. Although Theophilus lived around 1120, the process he described may be much older. The use of nitric acid then is a relatively new development, though when and where it originated has not been established. We first hear of the acid itself in the writings of pseudo-Geber, probably belonging to the late thirteenth century.2 It is quite likely that acids had been in use for a considerable time for alchemical experiments without being used for practical purposes. Beckmann mentions an old tradition that nitric acid was first used in the selparation of precious metals by some Germans in Venice.3 He also tells