130

ON MEASURES
half the labour necessary for its production in
1600, while in the latter case we could not tell
whether the quantity of producing labour in
the cloth had been reduced one half, or whether
that required for the production of money had
been doubled. In answer to this I say, that the
ratio between the quantities of labour necessary
for the production of cloth in 1800, and in
1600, might be equally ascertained, although
the quantity of labour employed in the produe-
tion of silver had varied, provided that the data
in the two cases were equal.

The data in the first case are the prices of
cloth at each period, and the ratio subsisting
between the quantity of labour employed at
gach period in the production of silver. The
circumstance of this ratio being that of equality
makes no difference.
Now suppose, in the second case, that we
are furnished with the prices of cloth at both
periods, and with the ratio subsisting between
the quantities of the labour necessary for the
production of silver, which ratio, by the sup-