THE NECESSITY FOR MINUTE STUDY OF THE AGE- 

 INCIDENCE OF CAUSES OF INFANT MORTALITY 



By JOHN S. PULTON, M. D., Baltimore, Md. 



In the Registration Area of the United States there occurred 

 in the year 1908 (U. S. Census Report on Mortality, 1908), 

 691,574 deaths, in a population of 45,028,767. Of this mor- 

 tality, that part which occurred under the age of one year num- 

 bered 136,432, or 19.73 per cent. The Registration Area in- 

 cludes those parts of the country which account for their 

 mortality, under effective registration laws, to within 10 per 

 cent of completeness. The population is estimated for inter- 

 censal years, but the population under one year of age is never 

 well accounted for even in census years. No country has ever 

 made a satisfactory enumeration of its population under one 

 year and infant mortality therefore cannot be stated in the usual 

 ratio to the thousand living. Nor can we, in this country, 

 follow the custom of other countries and state the infant mor- 

 tality in ratio to the thousand born alive during the year; for 

 births are not registered with completeness anywhere in the 

 United States, within or without the Registration Area. 



While we are less informed about population than about 

 deaths under one year, we may, nevertheless, make some sig- 

 nificant distinctions with respect to population. The population 

 of the Registration Area, in its age distribution, gives a profile 

 somewhat unlike that of the aggregate population, of which it 

 forms a little more than half. It shows the influence of urban pop- 

 ulations more than the aggregate population does, having, in the 

 young adult period a larger deviation of excess which is due 

 largely to foreign immigration, is likely to persist for many 

 years, and explains in part our relative apathy on such subjects 

 as infant mortality and birth registration. The population 

 the Registration Cities shows the same deviation, increased 

 by internal migration, strengthening the cities at the expense 

 of rural districts and small communities. Four city profiles 

 are shown ; that of Baltimore as typical of the older and 

 more stable American cities ; that of St. Paul and Minneapolis 

 combined, as typical of the younger cities in the Middle West; 

 that of Washington showing extreme variation from the type 

 regularly occurring in the Eastern cities; and the profile of all 

 the Registration Cities combined. The profile of the aggregate 

 population of the United States is also shown, as it was in 1900. 

 That for the Registration Area is not shown. Since 1900, 



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