If polluted water, vitiated air. bad drains, damp sites, overcrowding and dirt, be really important factors in the causation of disease, then it should be demonstrable that the improvements in these matters, which have been going on for the last half-century, have resulted in a material diminution of disease and death. Such evidence is abundantly forthcoming, in this and other countries, in the diminution which has been brought about in the death-rate. In the absence of statistics of population, no positive statements can be made as to death-rates in England before the rise of modern sanitation, but it seems fairly clear that in the eighteenth century the death-rate was at least double what it is now. It is not till the middle of the present century that detailed mortality-statistics are available. In 1858 the death-rate for England was 28.1 per thousand per annum; it has now for ten years past averaged rather less than 20, and indeed, in 1894, it reached the unprecedentedly low figure of 16.6 per thousand, though in 1895 it again rose to between 18 and 1 The reduction has been a gradual one, and much of it is due to a redaction in child-mortality. Ogle calculate that, contrasting the periods of 1841-70 and 1881-85, the mean annual mortality has fallen by 12.44 per cent for males, and 14.95 per cent for females. Figures from abroad are equally instructive. Between 1871 and 1892 the city of Berlin spent no less than nine and a half millions sterling on sanitary works. In 1876 its death-rate was 29.32 per thousand, and this has steadily diminished to 20.89 in 1892. That for the whole German Empire shows a very similar drop, from 29 per thousand in 1872 to 22.3 in 1894. During the above-mentioned period in Berlin the infant-mortality has fallen by nearly one-half. In Paris also, in which city great sanitary progress has been made, the death-rate has fallen from 25.37 in 1880 to 21.8 in 1893.

It must of course be remembered that the effect which sanitation can produce upon the death-rate is a limited one: we must all die sooner or later. Its effects are shown less in a decrease in the general death-rate than by its influence on so-called preventible diseases - notably on zymotics and tuberculosis. Some zymotics appear to be little influenced by sanitary improvements: measles and whooping-cough show no diminution, diphtheria has even increa.»ed. The decrease in small-pox mortality is due mainly to vaccination, and cannot fairly be adduced in evidence. But typhus fever, which in 1869 killed 193 per million living, has gradually abated till, in 1891, it killed only 5 per million. It has been practically abolished from the south of England, and the same is true of relapsing fever. Scarlet fever, at the commencement of Queen Victoria's reign, was killing her subjects at the rate of 797 per million per annum; in the quinquennium 1886-90 this number had fallen to 241, and in 1894 it was only 167. Typhoid fever, the mortality from which is. perhaps, the surest index of sanitary condition, has declined from a death-rate of 390 per million in 1869 to 168 in 1891, and 159 in 1894. The terrible mortality which cholera formerly caused when introduced into this country has become a thing of the past; within the last few years it has been many times introduced, and has failed to obtain any foothold at all. The mortality from phthisis shows a reduction almost as striking as that from zymotic disease. In 1838 no less than 3996 persons per million of the population died from this cause. The number has very gradually and steadily decreased to 1599 per million in 1891. How important a share sanitation can play in the reduction of phthisis-mortality is shown by Buchanan's well-known figures dealing with the effects of drainage in certain towns; in Ely the phthisis death-rate was reduced by 47 per cent, and in Salisbury by 49 per cent, by this means alone.

The death-rates in town and country are not alike: the aggregation of people in large towns has always produced a prejudicial effect on health.

From 1882-86 the urban death-rate per thousand was 203, the rural 177. In 1894 the figures were respectively 17.1 and 15.6. Urban and rural death-rates are gradually approximating as towns become more healthy. It would be easy to multiply figures, but enough has been said to prove the enormous part which sanitation has played in reducing the mortality from preventive