April — sept. 1859.] Ancient and Modem times. 83 



undergone no alteration, and the same number of pounds, shil- 

 lings, and pence have contained very nearly the same quantity of 

 pure silver. 



Until 1816 the Troy pound of standard silver was coined into 

 62 shillings ; the mint price of silver, therefore, was 5s. 2d. an 

 ounce. This continues so ; although since that year the pound is 

 coined into 66 shillings. The additional four are retained as 

 seignorage. 



Many ancient silver coins (I might say most), and many modern 

 Oriental, contain no intentional alloy — their only impurity is a 

 trace of gold or copper. In the modern European currencies, on 

 the contrary, every trace of gold is carefully removed and copper 

 added — the former for economy, the latter to give greater dura- 

 bility to the coin. Alloying for this purpose is even more neces- 

 sary to silver than to gold ; because the less the value of the coin, 

 the greater its circulation — a shilling changes hands more than 

 twenty times as often as a sovereign, and is therefore more than 

 twenty times as exposed to wear. 



Copper added to silver increases its sonoriety* and hardness. 

 The maximum degree of the latter is presented by an alloy of |-th 

 silver with ^-th copper, but so much hardness is unnecessary — 

 so much depreciation unadvisable. The color of the silver is but 

 very slightly impaired by the alloy — even equal weights of the 

 metals giving a white compound, 



When any alloy of silver and copper — the standard metal for 

 English or French silver coins, for instance, is exposed to a red 

 heat in air, the surface becomes black from the formation of a 

 film of oxide of copper. If the piece be now immersed in hot sul- 

 phuric acid, the superficial black is removed and a beautiful white 

 surface remains. Blanks for coins are treated thus before being 

 struck. Hence the whiteness of new silver pieces, as well as their 

 darker appearance after wear — the alloy beginning to show itself 

 when the pure silver surface has been removed. 



English standard silver contains 11*10 silver and 0-90 copper. 

 A pound Troy therefore consists of 1 1 oz. 2 dwts. of silver and 

 18 dwts. of copper. The metals dilate a little in combination — 



* Copper is the most sonorous of metals. 



