The chief index or measure of the health of any locality is what is called “the death-rate” of that locality. Although there are several other important evidences as to the healthiness or unhealthiness of any given area, the “death-rate” is the chief and most obvious indication of the advantageous or disadvantageous action of the conditions of any given city or other chosen area upon human life. Its records are more easily kept with an approach to accuracy than are records of cases of sickness not terminating in death. The cause of death has to be certified in civilised communities by a medical man; the total number of deaths in a year is given by the number of burial certificates. The death-rate is stated at so many per thousand of the population per annum. Thus, in a city of 5 million inhabitants,—that is to say, 5 thousand thousands—a record of eighty thousand deaths in the year gives 16 deaths for every thousand persons living. That is called “an annual death-rate of 16.” The record for any single month may be stated (as it is stated at intervals in the newspapers) “as at the rate of so many in the thousand per annum,” by multiplying the actual monthly number per thousand by 12. Thus, in the case of the city just cited, if the death-rate were the same in every month of the year—namely, 16—it would mean that 6500 persons died regularly every month. But we should probably find that in some month or other as few as 5417 persons died. That would be reported “as at the rate of” 13 per thousand per annum; since, if every month gave only 5417 deaths, we should get 65,000 deaths a year, which works out at 13 in the thousand in a population of 5 millions. In other months it might run as high as 19 or 20 (representing over 8000 deaths a month), although, taking all the months together, the deaths are at the rate of 16 in the thousand for the year.

The bald statement of the death-rate, of course, admits of much analysis where proper records are kept. Thus the death-rate from different diseases and groups of diseases can be stated, and the death-rate in each group at different ages and for the two sexes can be given where proper records are kept. In this country the records of population in various areas and for the whole country, and of the deaths from various causes, and at different ages, are collected and tabulated by the Registrar-General and his officials. The annual reports issued by him show what an amazing progress has been made in increasing the security of life in our great cities within the last fifty years. Thus, in London, the death-rate was, fifty years ago, 24 in the thousand. In 1906 it was only 15.1 in the thousand—it has gradually fallen, year by year, so that now it is less than two-thirds of what it was half a century ago. In Manchester and Liverpool it was about 26 twenty years ago, and has fallen to 19 in Manchester and to a little over 20 in Liverpool. In the same period the improvement has been (omitting fractions) from 19 to 14 in Bristol; from 20 to 16 in Birmingham; from 20 to 14 in Leicester. This great diminution in the death-rate has been coincident with the expenditure of public funds on the improvement of the water supply and the sewage arrangements of those cities, as well as with the enforcement of regulations to prevent overcrowding, and with the demolition of the most insanitary houses. Rules as to the removal of filth from the neighbourhood of dwelling-houses have been obeyed, and sick persons suffering from infectious diseases have been removed from dwelling-houses and conveyed to special hospitals. There is no doubt that the diminished death-rate is due to the action thus taken, and more will be done in the future to the same end. The proper provision of pure milk (at a reasonable price) for the food of the youngest children, of regular meals for older children, and the protection of adults from the too frequent inducement to indulge in the use of distilled spirits, will be taken in hand by the municipalities, and lead to a further diminution in the death-rate.

We may, indeed, soon have to ask whether, in a population which has become so much less subject to diminution by death than was formerly the case, there is not too great an increase by birth—too great, that is to say, for the existing means of employment and food-production. A most serious, indeed, an alarming fact, has recently come to light in the study of this question, namely, that the increase of the population is due (as pointed out on p. 279) to the proportionately larger number of births amongst the poorer, and even destitute, sections of the community who have not the means of training and rearing their children satisfactorily, and are themselves likely to transmit incapacity of one kind and another to their offspring; whilst those who have valuable hereditary qualities and are prosperous have—it is clearly established—relatively few children—and, in fact, do not increase the population. Whether this condition of things constitutes a real danger, how it will ultimately work out if left alone, and how the difficulty is to be met, are problems for statesmen which cannot be solved off-hand, but require knowledge not only of the crude facts of statistics, but also of the causes at work. Scientific knowledge—that is to say, thorough and unassailable knowledge—of the laws of heredity, of psychology, and of the natural history of human populations, are among the essential qualifications for those who have to face and deal with this difficult matter. And who is there who has this knowledge or is even trying to obtain it? Not the State in this country or its officials: for in every department of government (however capable some of the subordinates may be) there is a determined opposition to and fear of Science on the part of the political and highly paid chiefs—the jealous fear due to complete and deadly ignorance.