you to bear in mind that all these investigations have been made by the state (England) with one sole object in view, viz., the improvement in human health; and for the lengthening out of human life of each individual man or women; certainly no object can be nobler, none more deserving the attention of learned men or of philanthropists or statesmen."
In corroboration of the view that this is frequently the governing principle in public health studies, it is found that treatises on sanitation and hygiene present an array of statistics concerning the rate of mortality, with theories as to the commercial value of the higher rate of prolonged existence. For example, it is shown that England has expended within a few years for public health six hundred million dollars. The rate of mortality was 22 per 1000 in 1875,20 in 1880, and 17 in 1889. The number of lives saved increased in 1880 to 55,000 and in 1889 to 142,000 and for the period 1880-9 to the enormous total of 858,591. According to the statistician Farr "these lives represent a capital of six hundred million dollars, so that in ten years the nation would have more than recovered the sum it expended, while in the calculation no account is taken of disease averted and there can be no figures for that which cannot be calculated, such as suffering prevented, health improved and life made happier." Dr. W. E. Boardman showed in the sixth report of the Massachusetts Board of Health that the annual loss to the commonwealth by preventable sickness is considerably over three million dollars, or in other words "in order to affect a reduction in the annual mortality at the rate of only four per thousand, the state might expend a capital of over fifty-three millions of dollars in sanitary improvements and the sum invested in this manner would continue to return interest at the rate of 6 per cent, per annum."
Again, a noted sanitarian has called attention to the fact that but little more than one third of the value of the natural length of life is realized even in civilized countries and he states that the function of the sanitarian is to "prevent unnecessary disease and thereby unnecessary mortality."
