variations of price, but some are much more so than others. In all commodities which are produced by human industry, the quantity of industry annually employed is necessarily regulated by the annual demand, in such a manner that the average annual produce may, as nearly as possible, be equal to the average annual consumption.

In some employments, it has already been observed, the same quantity of industry will always produce the same, or very nearly the same quantity of commodities. In the linen or woollen manufactures, for example, the same number of hands will annually work up very nearly the same quantity of linen and woollen cloth. The variations in the market price of such commodities, therefore, can arise only from some accidental variation in the demand. A public mourning raises the price of black cloth.