Dirt is doubtless unhealthful, but the amount of ill health or the number of infant deaths caused by a home being dirty can hardly be measured, when, as is usually the case, the dirt is accompanied by so many other bad conditions arising from poverty. For example, a home in close proximity to railroad tracks or mills whose stacks send forth clouds of soot, smoke, and ashes is generally the poorly built home of those who have neither time nor means to secure and retain cleanliness under such difficulties. Overcrowding in homes is another factor the relative importance of which can not be exactly determined, because of its close connection with other ills. But the degree of overcrowding is greatest in the small cheaper houses, those of one, two, three, or four rooms. The average number of persons per room in the homes of all live-born babies for whom the data were secured was found to be 1.38. Homes of four rooms were more numerous than those of any other size and they housed an average of 1.58 persons per room. The number of babies in homes of various sizes with the number of persons per room for homes of each size was as follows: TABLE 5.—NUMBER OF BABIES LIVING IN HOMES OF EACH SPECIFIED SIZE, AND AVERAGE NUMBER OF PERSONS PER ROOM IN HOMES OF EACH SIZE. Size of home Live-born babies Persons per room All homes 1,463 1 room 33 4.42 2 rooms 165 2.27 3 rooms 147 1.83 4 rooms 526 1.58 5 rooms 222 1.22 6 rooms 233 1.07 7 rooms 38 .96 8 rooms 43 0.83 9 rooms 22 .93 10 rooms 4 .88 11 rooms 4 .64 12 rooms 1 .75 13 rooms 1 .69 14 rooms 2 .43 Not reported 22 In homes of one, two, three, or four rooms or where the number of occupants ranged from 4.42 to 1.58 persons per room the infant mortality rate was 155, as compared with a rate of but 101.8 in larger homes, where the number ranged from 1.22 to 0.43 persons per room. The 1910 census returns show that the greatest overcrowding was in ward 15, where the average number of persons per dwelling was 9.9. Wards 16, 11, and 14 came next with rates of 8.3, 7.7, and 7.2 respectively. The infant mortality rate for these four wards is 190.2, which is over one-third more than the rate for the whole city.