Dollar gold to silver ratio be exactly 15.5. Then a pennyweight of gold, that is 24 grains of gold, is nearly equal in value to a dollar of silver (1 dwt of gold = $1.002 of silver). Second, a dollar of gold is nearly equal in value to a pound of silver ($1 of gold = 5754 3/8 grains of silver = 0.999 Lb of silver). Third, the number of grains in a dollar (371.25) roughly equals the number of grams in a troy pound (373.24). The actual process of defining the US silver dollar had nothing to do with any
Troy weight on the continent. The troy ounce and grain were also part of the apothecaries' system. This was long used in medicine, but has now been largely replaced by the metric system (milligrams). The only troy weight in widespread use today is the British Imperial troy ounce and its American counterpart. Both are currently based on a grain of 0.06479891 gram (exact, by definition), with 480 grains to a troy ounce (compared with grains for an ounce avoirdupois). The British Empire abolished the 12-ounce troy pound in the 19th century, though it has been retained (although rarely used) in the American