But when the demand rises beyond what this quantity can supply, when it becomes necessary to raise food on purpose for feeding and fattening hogs, in the same manner as for feeding and fattening other cattle, the price necessarily rises, and becomes proportionably either higher or lower than that of other butcher's meat, according as the nature of the country, and the state of its agriculture, happen to render the feeding of hogs more or less expensive than that of other cattle.