arying
degrees of gravity in the prognosis of cases in which at the moment of
conception both parents are the subjects of lead poisoning, also when
one alone is affected. The malign influence of lead is reflected upon
the fetus and upon the continuation of the pregnancy 94 times out of 100
when both parents have been working in lead, 92 times when the mother
alone is affected, and 63 times when it is the father alone who has
worked in lead. Taking seven healthy women who were married to lead
workers, and in whom there was a total of 32 pregnancies, Lewin (Berlin)
tells us that the results were as follows: 11 miscarriages, one
stillbirth, 8 children died within the first year after their birth,
four in the second year, five in the third year and one subsequent to
this, leaving only two children out of 32 pregnancies as likely to live
to manhood. In cases where women have had a series of miscarriages so
long as their husbands worked in lead, a change of industrial
occupation on the part of the husband restores to the wives normal
child-bearing powers." The data of Constantin Paul, published as long
ago as 1860, indicated that lead exercised an injurious effect through
the male as well as the female parent. This sort of evidence is
certainly weak, in that it fails to take into account the possible
effects of environment; and one would do well to keep an open mind on
the subject. In a recent series of careful experiments at the University
of Wisconsin, Leon J. Cole has treated male rabbits with lead. He
reports: "The 'leaded' males have produced as many or more offspring
than normal fathers, but their young have averaged smaller in size and
are of lowered vitality, so that larger numbers of them die off at an
early age than is the case with those from untreated fathers."

[Illustration: EFFECT OF LEAD AS A "RACIAL POISON"

FIG. 7.--That lead poisoning can affect the germ plasm of
rabbits is indicated by experiments conducted by Leon J. Cole at the
University of Wisconsin. With reference to the above illustration,
Professor Cole writes: "Each of the photographs shows two young from the
same litter, in all cases the mother being a normal (nonpoisoned)
albino. In each of the litters the white young is from an albino father
which received the lead treatment, while the pigmented offspring is from
a normal, homozygous, pigmented male. While these are, it is true,
selected individuals, they represent what tend to be average, rath