These conditions, indeed, are in obvious mutual relation. To human life there has been affixed a normal range of duration; and when it prematurely fails--when children perish in the cradle, or adults amid the glow of manhood, the exception in every case is a thing to be investigated and explained. Of the 15,597 persons who have died within your jurisdiction, not an eighth part had reached the traditional ‘threescore years and ten;’ while nearly three-eighths died in the first five years of life. In proportion as facts like these appear in the death-tables of a particular district, in the same proportion we can trace the local prevalence of particular diseases, to explain the abridgment of life; and passing from such a locality to other districts, where the natural term of existence is more nearly attained, invariably we find that these diseases have fallen into comparative inertness. Finally, in grouping the fatal results of such diseases in their proportionate geographical allotment, invariably we find that their prevalence or non-prevalence, here or there, has been associated with demonstrable physical differences; that life has not capriciously been long in one place and short in another, but that, where short, it has been shortened; that its untimely extinction has depended on the direct operation of local and preventable causes. In this recognition of cause and effect, which the experience of late years has rendered vivid and precise; and in that higher appreciation of human life, which belongs to civilized nations in peaceful times; and in that deeper sympathy for the suffering poor, which should be at the heart of every Christian government, sanitary legislation had its origin in this country; and it has been the good fortune of the City of London (in respect of your two Acts of Parliament) to precede the rest of the metropolis in acquiring and exercising authority for the mitigation of preventable disease.