OF LABOUR. 
49 
the labourer receives. This quantity of silver 
expresses the value of his labour, in the same 
way that a certain quantity of silver expresses 
the value of a yard of cloth. Now the quan- 
tity of ‘silver by which the value of a yard of 
cloth is expressed, we term the price of the 
cloth, and, in a manner strictly analogous, the 
quantity of silver by which the value of a day’s 
labour is expressed, we term the wages of la- 
bour. The price of cloth and the wages of labour 
are so far exactly correspondent expressions. 
But when I speak of the price of cloth as the 
subject of causation or change, I do not intend 
the silver itself. The price of the cloth may 
be twenty shillings, but what causes the price 
is not what causes that quantity of silver. To 
consider the price as being or consisting in the 
actual silver itself, is an error of the same kind 
as to consider the length of a piece of timber 
as consisting in the instrument which we em- 
ploy to measureit. Were to speak of the real 
value of the price of cloth, or of the labour and 
capital employed in producing the price of