6i8 



THE POPULAR SCIENCE MONTHLY 



some five higher than England, which 

 has given to France a stationary, and 

 last year a decreasing, population. 



It is a question of fundamental im- 

 portance whether the relation between 

 the birth rate and the death rate will 

 be maintained under existing condi- 

 tions so as to give an increased or, at all 

 events, a stationary, population. Will 

 both continue to decrease, will they 

 remain approximately as at present, or 

 will the balance of the nineteenth cen- 

 tury be lost as has apparently hap- 

 pened in France? The death rate has 

 been halved by the practical abolition 

 of war, pestilence and famine in their 

 grosser forms, and by alleviation of 

 their milder aspects — improved condi- 

 tions for the struggling classes, the 

 limitation and mitigation of disease, 

 and better conditions of living. There 

 is abundant room for further improve- 

 ment, and it is stated by reputable 

 authorities that the death rate can be 

 halved again. But this is impossible; 

 indeed, it seems that in certain nations 

 the death rate has now reached its 

 minimum. Australia and New Zealand 

 now report a death rate of ten. This 

 means that in a stationary population 

 the average age at death is 100 years. 

 For every infant that aies, a man must 

 live to be 200 years old, or ten men 

 live to be 110. This is almost beyond 

 the limit of possibility. In 1910 the 

 death rate in England and Wales was 

 13.5. This means in a stationary pop- 

 ulation an average age at death of 74 

 years, and as more than one seventh of 

 all infants die, the average age of those 

 surviving infancy would be about 85. 

 The expectation of life of those 40 

 years old, which has not increased in 

 the course of the last sixty years in 

 spite of the lower death rate, is 28 

 years, so they die at the average age 

 of 68 years. 



The paradox is explained by the age 

 constitution of the population. Owing 

 to the high birth rate in England prior 

 to 1876 and its subsequent decrease, 

 an unusually large percentage of the 



population is from 5 to 40 years old, 

 at which age the death rate is on the 

 average only five per thousand. The 

 population of England has about 

 doubled by natural increase since 1850. 

 Consequently old people more than 

 sixty years old represent a population 

 only half as great as children, and if a 

 stationary population should hereafter 

 be maintained, the percentage of old 

 people would double. Indeed, as the 

 death rate of children and of those 

 under forty has decreased and will still 

 further decrease, the percentage of old 

 people will increase perhaps threefold. 

 At present there are in France about 

 as many people over sixty-five as there 

 are children under five, while in Eng- 

 land there are less than half as many, 

 and in Russia with its high birth rate 

 and death rate there are less than a 

 third as many. The death rate of those 

 over sixty-five is about 100; it has not 

 decreased in the past sixty years, and is 

 not likely to decrease considerably in 

 the future. These old people now form 

 about one thirtieth of the English pop- 

 ulation and contribute about three and 

 a third units to its death rate; when 

 they increase threefold, they will con- 

 tribute ten units, and, if other condi- 

 tions remain the same, the death rate 

 will rise from 13.5 to 20. There will 

 surely be a further decrease in the 

 death rate of those under forty, but 

 this will increase the number of those 

 over forty, and will tend to increase 

 their death rate. Probably a death 

 rate of 15 — an average age for those 

 surviving infancy of from 75 to 80 — is 

 as low as will ever be permanently 

 maintained by any nation. One may 

 well wonder whether the birth rate will 

 cease to decrease before or when it 

 reaches the minimum death rate. 



BE. LEWIS BOSS 



There is no Nobel prize in astron- 

 omy, otherwise America would have 

 had greater claims for the award than 

 has been the case in medicine, physics 

 and chemistry. It is a curious fact 



