I only add, that I do not pretend that in fact slavery in antient times did every where contribute to population, any more than I can affirm that the spirit of industry in the Dutch is common to all free nations in our days. All that is necessary for my purpose is, to set forth the two principles, and to shew the natural effects of the one and the other, with respect to the multiplication of mankind and advancement of agriculture, the principal objects of our attention throughout this book. I shall at present enlarge no farther upon this matter, but return to where I left off in the preceeding chapter, and take up the farther examination of the fundamental distribution of inhabitants into labourers and free hands. ------------------------------------------------------------------------ CHAP. VIII. _What Proportion of Inhabitants is necessary for Agriculture, and what Proportion may be usefully employed in every other Occupation?_ I have proposed this question, not with an intention to answer it fully, but to point out how, with the proper lights given, it may be answered. As I write under circumstances not the most favourable for having recourse to books, I must employ those I have. The article _Political Arithmetic_, of Mr. Chambers’s Cyclopedia, furnishes me with some extracts from Sir William Petty, and Dr. Davenant, which I here intend to employ, towards pointing out a solution of the question proposed. These authors consider the state of England as it appeared to them, and what they say is conclusive only with respect to that state. Sir William Petty supposes the inhabitants of England to be six millions, the value of grain yearly consumed by them ten millions sterling, the bushel of wheat reckoned at 5_s._ and that of barley at 2_s._ 6_d._ If we cast the two together, and reckon upon an average, this will make the quarter, or eight bushels of grain, worth 1_l._ 10_s._ but in regard, the barley cannot amount to one half of all the grain consumed, especially as there is a good quantity of rye made use of, which is worth more than the barley, though less than the wheat; let us suppose the grain worth 32_s._ _per_ quarter, at a medium; then ten millions sterling will purchase six millions of quarters of grain, or thereabouts: which used for nourishment, in bread and beer, gives the mean quantity of one quarter, or 512 pounds of grain for every inhabitant, including the nourishment of his proportional part of animals; supposing that Sir William attended to this circumstance, for it is not mentioned by Chambers. And I must observe, by the by, that this computation may hold good as to England, where people eat so little bread; but would not answer in France, nor in almost any other country I have seen.