The assumption explicitly made by General Walker that among the immigrants no influence was yet excited in restriction of population, is also not only gratuitous, but inherently weak; the European peasant who landed (where the great majority have stayed) in the eastern industrial states was thrown suddenly under the influence of the forces just referred to; forces possibly of stronger influence upon him than upon native classes, which are in general economically and socially more stable, On the whole, the better opinion is probably that of a later authority on the vital statistics of the country, Dr John Shaw Billings,i that though the characteristics of modern life doubtless influence the birth-rate somewhat, by raising the average age of marriage, lessening unions, and increasing divorce and prostitution, their great influence is through the transmutation into necessities of the luxuries of simpler times; not automatically, but in the direction of an increased resort to means for the prevention of child-bearing.
In this case diminished prolificity where unaccompanied by a decrease in the number of marriages at reproductive ages, is attributable to the voluntary restriction of child-bearing on the part of the married.
Marriage and child-bearing, in the first place, are operative amongst a fraction of the population only - those of conceptive age; whereas to the Urn of Death, as Dr Farr expressed it, all ages are called upon to contribute in their differing degrees.
Women of child bearing age should not use this drug due to the severely damaging effects it can have on unborn male fetuses.
Still, there are plenty of young couples who begin having children in their twenties, and that means there's probably lots of child-bearing years ahead.