BOOK VII . 255 The 9th needle silver and of 15 duellae of 9 duellae of gold , , 10th 14 10 a 99 99 99 99 „ nth 13 11 ft 99 99 99 99 „ 12th 12 12 tt 99 99 99 99 „ 13th 13 11 ft 99 99 99 99 „ 14th 14 10 tt 99 99 99 99 „ 15th 15 9 99 99 99 99 99 „ 16th 8 16 99 99 99 99 99 „ 17th 7 17 99 99 99 99 99 6… … By the first eleven needles , when they are rubbed on the touchstone , we test what proportion of gold a bar of silver contains , and with the remaining thirteen we test what proportion of silver is in a bar of gold ; and also what proportion of either may be in money . Since some gold coins are…
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