Book VIII metals, precious such as gold, platinum, silver Page 197



	BOOK VIII 185 emperor wished to have every opportunity for fraudulent practice brought under the law. We do not know if it is customary to mix other metals with gold or whether it was customary in the past. We shall now consider silver. The artisans who coin silver have mixed copper with it at various times and continue to do so today by various methods that I shall discuss in a book I am going to write, De Precio Metal-lorum et de Monetis^.26Both coin and bar silver usually contain some copper, commonly one and one-half ounces of copper to eight and one-half ounces of silver. Silversmiths make every effort to add as much copper to their silver as the law will permit. The ratio of copper to silver is not universally the same. Some may add more or less copper and chemists sometimes plate copper with silver and sell it as pure silver although this fraud is a capital offense equal to that of the men who coin money and depreciate the silver by adding a large proportion of tin and even iron. The denarius of Antonius was depreciated in this manner according to Pliny. I shall now consider tin which is more valuable than copper. According to Pliny one part of copper was added to two parts of tin in making an imitation of stannum. We do not use this alloy. Today tin smelters usually add one part of lead to nine parts of tin and use this alloy to cast non-malleable articles of different kinds such as small dishes, goblets, plates, platters and spheres. Two pounds of lead are often added to one hundred pounds of copper. When the copper is finished in the hearth and the carbon is pushed back the upper part will be stiff although the surface is still soft. The copper refiner then seizes the lead with his tongs and pushes it through the surface to the center of the mass so that it will be taken up by the copper. This makes a softer copper and coppersmiths are more willing to work with it than with copper that contains no lead. Some people have added lead to copper, as we learn from Flavius Vopiscus, and made copper coins that were valueless. Antonius mixed iron with copper. Such frauds have been perpetrated by many men. On the other hand, Pliny praises the art of the famous Aristonides who, when he wished to portray the fury of Athaman wishing to destroy his son Clearchus and having destroyed him being overcome with remorse, mixed iron and copper so that the rust of the iron showed through the luster of the copper thus portraying the red blush of shame. Thus a small quantity of a base metal is mixed with a large mass of precious metal in so many ways. From all of these frauds men make money but this is ultimately taken away. On the other hand Aristonides made an alloy from which art has profited. There is no law to prevent the alloying of a small amount of precious metal with a large amount of base metal. It is no crime to mix a pound of ²⁶ De Precio Metallorum et de Monetis was first published in three books in 1550 at Basel, together with De Mensuris et Ponderibus. It treats of the value of money and metals, their weights and impurities.