pper classes and
lower in the poorer classes. Observations of boys who were inmates of
workhouses gave a mean specific gravity of 1,052.8 and on schoolboys
a mean of 1,056, while among the undergraduate students of Cambridge
University he found a mean of 1,059.5. Several men of very high
specific gravity in the last group had distinguished themselves in
athletics. "Workhouse boys are in most cases of poor physique, and
one can hardly find a better antithesis than the general type of
physique common among the athletic members of such a university as
Cambridge."[65] There is no more conclusive evidence of an organic
difference between man and woman than these tests of the blood.
They permit us to associate a high specific gravity, red corpuscles,
plentiful haemoglobin, and a katabolic constitution.

A comparison of the waste products of the body and of the quantity
of materials consumed in the metabolic process indicates a relatively
larger consumption of energy by man. It is stated that man produces
more urine than woman in the following proportion: men, 1,000 to 2,000
grams daily; women, 1,000 to 1,400 grams. As age advances, the amount
diminishes absolutely and relatively in proportion to the diminution
of the energy of the metabolic process. A table prepared from adults
of both sexes, twenty-five years of age, of the average weight of
sixty kilograms, shows a larger proportion both of inorganic and
organic substances in the urine of men.[66] Milne Edwards has found
that the bones of the male are slightly richer in inorganic substances
than those of the female.[67]

The lung capacity of women is less, and they consume less oxygen and
produce less carbonic acid than men of equal weight, although the
number of respirations is slightly higher than in man. On this account
women suffer deprivation of air more easily than men. They are not so
easily suffocated, and are reported to endure charcoal fumes better,
and live in high altitudes where men cannot endure the deprivation of
oxygen.[68] The number of deaths from chloroform is reckoned as from
two to four times as great in males as in females, and this although
chloroform is used in childbirth. Children also bear chloroform
well.[69] Women, like children, require more sleep normally than men,
but "Macfarlane states that they can better bear the loss of sleep,
and most physicians will agree with him.... One of the greatest
difficulties we have to contend with in nervous