THE PROGRESS OF SCIENCE 



4i5 



The Magnetic Work of the Department of Terrestrial Magnetism, showing the 



ocean cruises and land stations. 



say, from a birth rate of 20 and a death 

 rate of 15. 



The curves that are reproduced show- 

 ing the death rates for each hundred 

 thousand of the population from certain 

 diseases can not be very accurate, as it 

 is in many cases impossible to assign a 

 single cause for death, and the returns 

 of physicians are incorrect in a large 

 percentage, perhaps in a majority, of 

 cases. Still the curves are instructive, 

 more especially in showing the decrease 

 in certain contagious and preventable 

 diseases, and the increase in certain or- 

 ganic diseases. In the short period of 

 eleven years the rate for tuberculosis 

 has decreased from 202 to 149; for in- 

 fant diarrhoea, from 109 to 70; for 

 typhoid fever, from 36 to 16; for diph- 

 theria, from 43 to 18. On the other 

 hand, the rate for heart disease has in- 

 creased from 123 to 151; for apoplexy, 

 from 67 to 75; for Bright 's disease 

 from 89 to 103, and for cancer, from 63 

 to 77. 



It is evident that people must die 

 some time and somehow; if they escape 

 from the diseases prevalent in the 



earlier years of life, they must die from 

 those of later life. It is also the case 

 that the decreases noted are far greater 

 than the increases. Still it is true that 

 the decrease in the death rate is in the 

 earlier age groups, while there has been 

 an increase after the age of fifty-five. 

 This has been attributed to the fact that 

 the conditions of modern life are unfav- 

 orable to peor le of middle age. The fact 

 seems to be, however, that the diseases 

 from which people are likely to die in 

 middle and old age are not to a con- 

 siderable degree preventable, and the 

 very fact that the lives of millions of 

 infants and young people who were 

 below the average in constitutional 

 strength have been saved must lead to 

 a higher death rate when they become 

 more advanced in years. 



THE WORE IN TERRESTRIAL 

 MAGNETISM OF THE CAR- 

 NEGIE INSTITUTION 



Among the large mass of important 

 scientific research conducted under the 

 auspices of the Carnegie Institution of 

 Washington and described in the annual 



