INFANT MORTALITY AND THE ENVIRONMENT. 221 



knowledge let us put ourselves iu liis place, and then we may 

 compreliend the exultation with which he announces the identity 

 of radiant heat and common air, for he feels that he is beginning 

 a daring revolt against the orthodox doctrine of caloric, and so 

 he is. 



[ To be continued. "[ 



INFANT MORTALITY AND THE ENVIRONMENT. 



By J. M. FEEJsCn, M. D. 



IT is a startling fact, which meets the student of vital statistics 

 at the outset of his investigations, that from one third to 

 one half of all persons born into the world die before reaching the 

 age of five years. Or, to face the terrible reality from another 

 point of view, so great are the dangers of infancy, that a child 

 which has completed its fifth year actually has an expectation of 

 life more than twelve years greater than it had at birth. 



The exact proportion of deaths varies greatly in different coun- 

 tries and localities, at different times and under different circum- 

 stances. Statistics are of value only in showing average results. 

 In Norway, for example, the proportion dying under five is stated 

 by Dr. Farr to be 204:'5 per 1,000 born ; while in England it is 338 per 

 1,000, and in Italy 567 per 1,000. In fifty-one so-called " healthy 

 districts " of England and Wales, according to the same authority, 

 the mortality under five is 175 per 1,000 born, while in the Liver- 

 pool district, representing the most unfavorable sanitary con- 

 ditions, it is 460 per 1,000. 



In the different parts of our own country, we find nearly as 

 great a variety as on the continent of Europe. Even in the same 

 latitude, the proportion varies greatly, according as city or coun- 

 try districts are considered. In the State of Vermont, which con- 

 tains no large cities, and represents essentially a rural population, 

 the number of deaths under five, for the year 1883, was 23*8 per 

 cent of the whole number of deaths ; in the State of Massachu- 

 setts, which embraces several large cities within its limits, for the 

 twelve years ending in 1884, it was 34'74 per cent ; and in the city 

 of New York alone, for the seven years ending in 1873, it was ex- 

 actly 50 per cent of the entire mortality. 



The younger the child, the larger is the death-rate. According 

 to Dr. Jacobi, more than half of those who die under five years of 

 age die in the first year. Dr. Curtiss states that, in all the great 

 cities of North America, out of every one hundred live-born chil- 

 dren, about twenty-five die before the end of the first year, and 

 from forty to fifty before the close of the fifth year. 



Death-rates like these — and the figures might be multiplied 



