This increased preservation of the sickly has had the effect of increasing the life period of an average child, and this increase in the life probability is often and very rightly cited as an indication of the improved sanitary conditions of the people. Improved sanitary surroundings, as we have seen, are taken advantage of chiefly by the sickly, and thus with our increased probability of life we have diminished the average robustness of constitution, or innate healthiness of the race, for a larger proportion of sickly ones are living amongst us. In our day a greater number of parents suffer from phthisical, scrofulous and other taints than in days gone by, and these and other taints are passed on to their children.
So far we have seen what of necessity follows from our biological premises, but it is also possible, I think, to show by statistics that already very observable deterioration has taken place.
If we examine one of the reports of the Registrar General for births, deaths and marriages, we shall gain pretty full information concerning the deaths from disease, accident, old age, etc., that have occurred during the last thirty or forty years.
In Report 54, Table 17, the annual death-rates from various causes per million of population are given, and arranged in groups of five years from 1858 to 1890. We have there a history of thirty years, and even in that time a notable change in this history is to be observed. I have arranged the greater number of facts given in Table 17 in the following table, so as best to bring out those points which we are discussing. In the first group of disease are those due to micro-organisms, and a diminution of these diseases to a marked extent is to be observed of late years. Phthisis and scrofula placed by themselves in this group share in this decrease. In the second group are diseases that are due in great measure to carelessness, want of management, neglect and ignorance, such as convulsions, diseases of dentition, parturition and registered accidents. These, too, as one would expect, diminish yearly in a country where surrounding comforts and a sense of responsibility are on the increase. When we turn to the third group, that of constitutional disease, where the hereditary tendency comes in, we find an increase in almost all the hereditary diseases. A tendency to an increase of neurotic affections is shown by an increase in the deaths from nervous diseases, suicide and intemperance. A large increase in the diseases of the respiratory system is due in part to the increasing number of tuberculous patients who, kept from inroads of microbes, nevertheless readily fall a prey to other affections: there is, too, an increase in diseases of the circulatory system, in cancer, diabetes and other constitutional diseases.