erysipelas and puerperal fever 9 _per cent._ fewer. Small-pox, it is true, is doubled; but the prevention of this disease rests, out of your jurisdiction, in the exercise of individual discretion. Under the item of infantile diarrhœa (included in the tenth column) there is likewise an increase of nearly a third;[36] an exception probably dependent on the fact that, during last year, many deaths which might have swelled this column were (on account of the then prevalent influence) catalogued under the head of epidemic diarrhœa or cholera. [35] _Appendix_, No. IX. [36] In the column referred to, this is concealed by the marked diminution, during the present year, of other disorders classed with infantile diarrhœa. Their reduction maintains the total of that column (notwithstanding the difference of diarrhœa) considerably less for this year than for last. I should be misleading your Hon. Court, and practising a deception which next year’s registry would expose, if I pretended that the striking difference between the two years’ several totals of preventable deaths (a difference which, leaving cholera out of the question, probably amounts to a diminution of 30 _per cent._ on the sum of last year) had resulted wholly, or even chiefly, from sanitary improvement, and could be interpreted as the evidence of permanent physical changes around the dwellings of our poorer population. I guard you against this impression now, because, however satisfactory it might be as a momentary belief, it would lead to subsequent disappointment; and any future rise in the proportion of these deaths would induce the erroneous, but disheartening, supposition that your later sanitary steps had been less successful than the first. In all these matters, and especially in analysing the details of a death-registry, it is requisite (as I have already stated) to deal with cycles of many years. Periods of pestilence are habitually followed by periods of diminished mortality: partly because population is diminished, and especially that share of the population which suffers most from obviable causes of disease; partly because the great alarm of death has induced vigilance and precaution, public and private, against the occasions and beginnings of illness. And, beyond both these circumstances, there are others which we cannot analyse or explain, though we have scientific certainty of their operation; circumstances which seem to ensure a comparative quiescence of the ordinary causes of zymotic disease during those periods which next succeed the prevalence of certain fatal epidemics.[37]