It seems hardly necessary to shew, how much the riches and strength of states depend upon the number of inhabitants. But perhaps there is not any country in which the certainty of this position is more indisputable than in Russia; for not only the strength of the empire, but the riches of every individual also, must be in proportion to the degree of population. If therefore in London, which enjoys the many advantages already recited, more than 2000 persons die annually of the Small Pox, we may surely suppose, that the loss which Russia in its whole extent sustains by this distemper in the same space of time, amounts to two millions of souls. And this havock must greatly retard the increase of the human species. There are some diseases peculiar to old age, which terminate a life almost entirely spent, and totally useless to the community. Such diseases, considered in a political sense, are not hurtful to the state. But the Small Pox spreads destruction chiefly upon the younger part of the species, from whose labours in their several callings the public might otherwise have expected advantages beyond all computation. The disappointment and loss incurred is of course neither to be calculated nor conceived. A discourse upon this subject might be extended to a great length; but it seems unnecessary to enlarge, especially when I consider to whose judgment this essay is with all humility submitted. The public, I am persuaded, must be sufficiently convinced from fact and demonstration, that Inoculation is the only means of preventing the mischiefs arising from the Small Pox. In a former treatise I have laid down a plan for an effectual method of general practice, by which the spreading of the natural Small Pox will be prevented, and the cure of the inoculated rendered as easy and safe as possible to the patient. I have therefore nothing more to add but my wishes, that the empire of Russia may meet with the utmost success from this discovery, under the reign of so illustrious and beneficent a Sovereign.