BOOK VII.
255
The 9th
needle
of 15 duellae of
silver and
9 duellae of gold
,, 10th
a
14
99
99
10
99
99
„ nth
ft
13
99
99
11
99
99
„ 12th
tt
12
99
99
12
99
99
„ 13th
ft
11
99
99
13
99
99
„ 14th
tt
10
99
99
14
99
99
„ 15th
99
9
99
99
15
99
99
„ 16th
99
8
99
99
16
99
99
„ 17th
99
7
99
99
17
99
99
„ 18th
99
6
99
99
18
99
99
„ 19th
99
5
99
99
19
99
99
„ 20 th
99
4
99
99
20
99
99
„ 2ISt
99
3
99
99
21
99
99
„ 22nd
99
2
99
99
22
99
99
„ 23rd
99
1
99
99
23
99
99
» 24th
9 9
pure gold
I i
By the first eleven needles, when they are rubbed on the touchstone, wetest what proportion of gold a bar of silver contains, and with the remainingthirteen we test what proportion of silver is in a bar of gold; and also whatproportion of either may be in money.
Since some gold coins are composed of gold and copper, thirteen needlesof another kind are made as follows :—