Page:Life of Sir William Petty 1623 – 1687.djvu/237

 supposes two acres of pasture land enclosed, and a weaned calf put out to graze there. In twelve months' time the calf will have become one hundred heavier, he thinks, in eatable flesh. Then one hundredweight of such flesh is the 'value or year's rent' of the land. He next supposes the labour of a man, for a similar period of twelve months, to make this same land yield sixty days' food of the same or any other kind. Then the overplus of days' food is the wages of the man, both being expressed by the number of days' food; and in this case land and labour will stand as five to six, the unit being the ordinary day's food of an adult man. This par, he declares, seems to promise to be as regular and constant as the value of pure silver; but he fails to show how it could be adapted in practice to the purposes of trade by any instrument of exchange, and the chapter in the 'Political Anatomy ' in which this disquisition occurs concludes, instead, with a fanciful sketch, how the par of land and labour just described could be extended to art and opinion, eloquence, and other matters: inquiries which, he ends by acknowledging, 'are perhaps not very pertinent to the matter in hand.'

The want of a proper circulating medium, both in quality and in quantity, was one of the great difficulties of the financiers of the reign of Charles II., and, as already stated, the confusion of coins is set down in the 'Treatise on Taxes' amongst the principal causes which unnecessarily increase and aggravate the public charges. A chapter is devoted to the arguments against raising, depressing, and embasing the coinage, in which the arguments now universally accepted are clearly stated. They hardly now need a place in a formal treatise on public economy, but at the time were still deemed doubtful and hazardous. Sir William also expressed himself as in favour of a single metallic standard, in a passage devoted to a further discussion of these topics in the 'Political Anatomy of Ireland.' In the same treatise he points out, with reference to the trade of Ireland, that the