My daily experience as a Surgeon--especially as a Hospital-Surgeon, enables me confidently to speak of these diseases as an artificial product of unhealthy exterior conditions. The contrasting results of surgical operations in town and in country--of operations undertaken amid pur-ventilation, in spacious cleanly rooms and dry localities, with those undertaken under opposite circumstances (in the dwellings of the poor for instance, or wherever else amid damp, dirt, and over-crowding), and the similar experience which exists as to the origination of puerperal fever, would be quite conclusive as to the fact, that of the 101 deaths under this head, a large majority might have been prevented. Next, in the sixth, seventh and eighth columns, stand deaths arising in the chief acute diseases of infancy, those to which the disproportionate mortality of infants is mainly due. Many careful statistical observations, as well as personal experience, convince me that the immense fatality recorded under this head, is, to a very great extent, due to obviable causes. To bring this matter distinctly before you, I must take, as a standard of comparison, some district where the general death-rate is sufficiently low to distinguish it as eminently healthy; and in such an one you will notice a marked diminution, not only (of course) in the _number_ of infant deaths, but likewise in their _proportion_ to the total mortality. Such a district is that of the combined parishes of Glendale, Bellingham and Haltwhistle, in the county of Northumberland. In it the general death-rate is 14; in the East and West London Unions of the City of London, the general death-rate is 26·73. In the former district, children under five constituting more than an eighth of the population (1/7·6), their deaths form about a quarter of the whole mortality; while in the latter district, where the children are in smaller proportion--namely about 1/9 of the population, their deaths are not much less than half (1/2·21) of the whole mortality. Thus, in the healthier district they die at less than double the average rate for all ages; in the unhealthier, at more than four times that average.