When we compare the precious metals with one another, silver is a cheap, and gold a dear commodity.
 Adam Smith, The Wealth of Nations (1776). copy citation

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Author Adam Smith
Source The Wealth of Nations
Topic commodity gold
Date 1776
Language English
Reference An Inquiry into the Nature and Causes of the Wealth of Nations
Note
Weblink http://www.gutenberg.org/files/3300/3300-h/3300-h.htm

Context

“The whole quantity, therefore, of the cheap commodity, must commonly be greater in proportion to the whole quantity of the dear one, than the value of a certain quantity of the dear one, is to the value of an equal quantity of the cheap one. When we compare the precious metals with one another, silver is a cheap, and gold a dear commodity. We ought naturally to expect, therefore, that there should always be in the market, not only a greater quantity, but a greater value of silver than of gold. Let any man, who has a little of both, compare his own silver with his gold plate, and he will probably find, that not only the quantity, but the value of the former, greatly exceeds that of the latter.” source