We will first take Sweden, which has had fairly complete national statistics longer than any other country, and we are now fortunately able to give the facts on the most recent official testimony—the Report furnished by the Swedish Board of Health to the Royal Commission, and published in the Appendix to their Sixth Report (pp. 751-56). Such great authorities as Sir William Gull, Dr. Seaton, and Mr. Marson, stated before the Committee of Enquiry in 1871 that Sweden was one of the best vaccinated countries, and that the Swedes were the best vaccinators. Sir John Simon’s celebrated paper, which was laid before Parliament in 1857 and was one of the chief supports of compulsory legislation, made much of Sweden, and had a special diagram to illustrate the effects of vaccination on small-pox. This paper is reproduced in the First Report of the recent Royal Commission (pp. 61-113), and we find the usual comparison of small-pox mortality in the last and present century which is held to be conclusive as to the benefits of vaccination. He says vaccination was introduced in 1801, and divides his diagram into two halves differently coloured before and after this date. It will be observed that, as in England, there was a great and sudden decrease of small-pox mortality after 1801, the date of the _first_ vaccination in Sweden, and by 1812 the whole reduction of mortality was completed. But from that date for more than sixty years there was an almost continuous _increase_ in frequency and severity of the epidemics. To account for this sudden and enormous decrease Sir John Simon states, in a note, and without giving his authority: “About 1810 the vaccinations were amounting to nearly a quarter of the number of births.” But these were almost certainly both adults and children of various ages, and the official returns now given show that down to 1812, when the whole reduction of small-pox mortality had been effected, only 8 per cent. of the population had been vaccinated. We are told in a note to the official tables that the first successful vaccination in Stockholm was at the end of 1810, so that the earlier vaccinations must have been mainly in the rural districts; yet the earlier Stockholm epidemics in 1807, before a single inhabitant was vaccinated, and in 1825, were less severe than the six later ones, when vaccination was far more general.