This is true, although certain problems respecting tuberculosis still need elucidation, e.g., as to improved methods of treating the diseases, and of increasing individual immunity during exposure to protracted infection. 2. Domestic protection is at once practicable against infected cows’ milk; and control of this source of infection at its source is also practicable. 3. Of the circumstances favouring the development of pulmonary tuberculosis industrial dust and domestic overcrowding are the most potent. More detailed and systematic supervision of factories and workshops is needed, followed by general adoption of remedies, which would increase industrial efficiency as well as reduce tuberculosis. 4. Tuberculosis is especially a “bedroom infection.” But improvement in housing is a dual problem, and it is a blunder to assume that improved housing, so long as the healthy and tuberculous sick continue to be housed together, will produce a rapid decline in the prevalence of tuberculosis. Hospital provision for the sick is as necessary as improved general housing. FOOTNOTES: [17] The substance of two lectures at the Summer School on Tuberculosis, Trudeau Sanatorium, Saranac, N. Y., July, 1919. CHAPTER X CHILD WELFARE WORK IN ENGLAND[18] The subject of child welfare, in its chief developments, cannot be separated from that of Public Health, of which it forms a constituent part, though I do not ignore the fact that child welfare is largely dependent also on the extent to which child labor is exploited, and to which expectant and nursing mothers,—as also other mothers whose extra-domestic employment or whose employment for gain is within the home itself,—involves neglect of young children. Improvement in child welfare has occurred as the sanitary and social progress of the country has advanced. Whereas in the decade 1871-80, when money began to be spent more freely on elementary sanitary reform, the expectation of life or mean after-lifetime at birth of males was 41.4 years and of females was 44.6 years; in the years 1910-12 these had increased to 51.5 and 55.4 years respectively. The greater part of the saving of life which this addition of ten years to the average duration of life was the result of reduced mortality in children under five years of age.