84 



BIOLOGY OF DEATH 



life for some group of people at some period in the more 

 or less remote past, and for comparison the expectation 

 of life, either from Grlover's table, for the population of 

 the United States Registration Area in 1910— the expec- 

 tation of life of our people now, in short — or equivalent 

 figures for a modem English or French population. 



Because of the considerable interest of the matter, 

 and the fact that the data are not easily available to 



YLMS.ar LIFE 



Fig. 19. — Comparing the expectation of life in the 17th century with that of the present time. 



biologists. Table 6 is inserted, giving the expectations of 

 life from which certain of the diagrams have been plotted. 

 Figure 19 gives the results from Halley's table, based 

 upon the mortality experience in the city of Breslau, in 

 Silesia, during the years 1687 to 1691. This gives us 

 a rough, but in its general sweep sufficiently accurate 

 picture of the forces of mortality towards the end of the 

 seventeenth century From this diagram it appears that 

 at birth the expectation of life of an individual born in 

 Breslau in the seventeenth century was much lower than 



