and of prolonging life were emphasized in a report made by Professor Irving Fisher to the National Conservation Commission. The desirability of further development and training of the human resources by means of education has already been emphasized in earlier readings. The problem of conserving natural resources is only one part of the larger problem of conserving national efficiency. The other part relates to the vitality of our population. The two parts are closely interwoven. Protection against mining accidents, forest fires, floods, or pollution of streams prevents not only loss of property, but loss of life. The prevention of disease, on the other hand, increases economic productivity. So far as we can compare vital and physical assets as measured by earning power, the vital assets are three to five times the physical. The facts show that there is as great room for improvement in our vital resources as in our lands, waters, minerals, and forests. This improvement is possible in respect both to the length of life and to freedom from disease during life. Contrary to common impression, there is no iron law of mortality. Recent statistics for India show that the average duration of life there is less than twenty-five years. In Sweden it is over fifty years, in Massachusetts forty-five years. The length of life is increasing wherever sanitary science and preventive medicine are applied. In India it is stationary. In Europe it has doubled in three and a half centuries. The rate of increase during the seventeenth and eighteenth centuries was about four years per century, during the first half of the nineteenth century about nine years per century, during the latter half of the nineteenth century about seventeen years per century, and in Germany, where medical and sanitary science has reached the highest development, about twenty-seven years per century. The only comparative statistics available in this country are for Massachusetts, where life is lengthening at the rate of about fourteen years per century, or half the rate in Germany. There is no need, however, of waiting a century for this increase. It could be obtained within a generation. Three-fourths of tuberculosis, from which 150,000 Americans die annually, could be avoided. Eighteen experts in various diseases, as well as vital statisticians, have contributed data on the ratio of preventability of the ninety different causes of death into which mortality may be classified. From these data it is found that fifteen years at least could be at once added to the average human lifetime by applying the science of preventing disease. More than half of this additional life would come from the prevention of tuberculosis, typhoid, and five other diseases, the prevention of which could be accomplished by purer air, water, and milk. In Lawrence, Mass., after the installation of a pure-water supply, the death rate from typhoid was reduced by 80 per cent. For every death thus saved from typhoid, two or three deaths are saved from other diseases. Judging from the English statistics of illness, we must conclude that at all times in the United States about 3,000,000 persons are seriously ill, of whom about 500,000 are consumptives. Fully half of this illness is preventable. If we appraise each life lost at only $1,700 and each year's average earnings for adults at only $700, the economic gain to be obtained from preventing preventable disease, measured in dollars, exceeds one and a half billions. This gain, or the lengthening and strengthening of life which it measures, can be secured through medical investigation. and practice, school and factory hygiene, restriction of labor of women and children, the education of the public in both public and private hygiene, and through improving the efficiency of our municipal, state, and national health service. Our National Government has now several bureaus exercising health functions, which only need to be concentrated under one department to become coordinated parts of a greater health service worthy of the nation. INDEX Agriculture, methods of (1650), 11; Balance of trade, theory, 128; between England and the colo- Bank, Land, 101; First United States, 485-493; Second United United States (1791), 487; state, Bounties, on colonial products, 127, 142. Building and loan associations, 839, Canals, proposals for building, 386– Cattle, 13, 15, 31, 37, 39, 41, 223, Character of people, in New York (1759), 112; in Virginia, 113; 356; (1860), 542-545; (1902), Cotton, growth of, 224, 566; kinds, 846-847. Cities, growth of, 358, 362; (1790- Coinage, history of (1791-1840), Colonization, cost of, 1; of Plymouth Conservation, of natural resources, Corn (Indian), method of cultivat- Cost of living (1698), 82; (1802), 271; (1817), 348; (1910), 810. 225; gin, invention of, 226; 599; manufactures of, 263, 283 Currency, in colonies, 97-99, 146, Debt, federal, 424, 425, 487; state, Drink, 834, 847. See Intemperance. Education, 273, 829, 843. Embargo, 214, 419, 424; effect on Erie Canal, route to the West, 361; Exports, colonial, 51-52 (tables), |