RT Journal
T1 THe span of human life
JF Journal of the American Medical Association
JO Journal of the American Medical Association
YR 1909
FD October 30
VO LIII
IS 18
SP 1490
OP 1491
DO 10.1001/jama.1909.02550180048005
UL http://dx.doi.org/10.1001/jama.1909.02550180048005
AB It is often asked if men do not live longer now than formerly—if the length of human life is not actually increased? It is evident that two distinct problems may be hidden in this question as it is ordinarily put. The first relates to what may be called the natural term of existence. The duration of a normal life not cut off by accident or infectious disease was placed by the Psalmist at about threescore years and ten; seventy or eighty years is, indeed, to-day commonly reckoned as the normal life.There seems to be no reason for supposing that within historical times man's natural term of life has materially varied. Like that of the dog or the horse, it is determined by unknown biologic causes. While some statements in old documents might be taken to indicate that in antiquity men lived hundreds and even thousands of years, such assertions