September 19, 1919] 



SCIENCE 



279 



politan mortality with that of the Registration 

 Area. Some of the more interesting facts 

 which have been established by this study may 

 be summarized. 



The mortality rate for pulmonary tuber- 

 culosis of the children of wage earners is not 

 higher than that of children of the general 

 population. This is all the more striking 

 when we consider that about one half of the 

 children in the Registration Area live in rural 

 communities. The decline in the death rate 

 from pulmonary tuberculosis during the years 

 1911 to 1916 is greater in the insured than in 

 the general population. The mortality from 

 organic heart disease is higher in wage earn- 

 ers than in the population at large, especially 

 during the working ages. This higher rate 

 persists to old age but to a less degree. Con- 

 trary to the general belief, there has been no 

 increase in the death rate for organic heart 

 disease in the period 1911 to 1916. Bright's 

 disease too is a more frequent cause of death 

 in the insured. 



Accidents rank fifth in the causes of death. 

 How serious this problem still is, and how 

 great the field for prevention is, is shown by 

 a comparison of the statistics of England and 

 Wales with those of the United States. In 

 1913, that is before the war, the accident 

 mortality for England and Wales for the ages 

 from 35 to 45 was 62.4 i)er 100,000. In the 

 United States it was 139.6 per 100,000 in the 

 Registration Area and 154.3 per 100,000 in 

 the insured males at the same ages. Indus- 

 trial policy holders suffer from a higher acci- 

 dent rate at the ages where the occupational 

 factor plays a part, and where too their death 

 works the greatest hardship to their families. 

 There has been little reduction in the accident 

 rates in the six years under study. During 

 the working years the suicide rate of male 

 workers is greater than that of the general 

 population. It is interesting to note that the 

 colored rate is one half of the white rate. 

 However the homicide rate for negro males is 

 seven and a half times as great as for the 

 entire group of insured wage earners. In the 

 age period 25 to 34 it ranks next to pneumonia 

 as a cause of death of negro males. 



The study of the diseases incident to preg- 

 nancy and the puerperium is of the utmost 

 importance. The statistics are based on the 

 age group 15 to 43, the child-bearing period. 

 In this age period these diseases cause more 

 deaths than any class of disease except pul- 

 monary tuberculosis. The rates are 66.1 -per 

 100,000 for whites, and 82.3 per 100,000 for 

 blacks. Puerperal sepsis caused 43 per cent, 

 of all the deaths, albuminuria and convulsions 

 26.4 per cent. The figures for the Registra- 

 tion Area are almost the same. There has 

 been some decline in the maternal death rate 

 in the six years under study. The decline in 

 the insured was 10.7 per cent., which was 

 greater than that in the general population. 

 The authors consider this a vindication of the 

 Metropolitan Life Insurance Company's system 

 of visiting nurses. These figures point out a 

 very important field for preventive medicine. 



The analysis of the cancer mortality rates 

 for the period 1911 to 1916 is instructive, for 

 it shows how unsafe it is to generalize. The 

 necessity of considering age groups, the sex 

 and race, as well as the site of the cancer, 

 before drawing inferences as to the increase 

 or decrease of cancer mortality is well brought 

 out. The statistics of the Metroiwlitan Life 

 Insurance Company show no definite increase 

 in cancer mortality in the six years under 

 study. 



I have mentioned but a few of the valuable 

 facts brought out in this volume. The au- 

 thors are to be congratulated on having made 

 an important and unique contribution to the 

 study of the incidence of disease among wage 

 earners, a study which will be of great assist- 

 ance to all who labor for the prevention of 

 disease, be they doctors, economists or social 

 workers. 



Ernst P. Boas 



SPECIAL ARTICLES 



THE INTERACTION OF GRAVITATING AND 

 RADIANT FORCESi 



1. Atmospheric Temperatures. — These rela- 

 tions are so interesting, not to say perplexing, 



1 Advance note from a Report to the Carnegie 

 Institution of Washington, D. C. 



