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relating to this disease as distinct from those relating to scarlet fever. The ages selected are—all ages,
ages under 3, from 3 to 10 years, and 10 years and upwards.
A study of the rates shows that—
(1) Antecedent to 1871-80 in groups of population when the diphtheria death rate at
all ages was rising, the rate at ages 3-10 years, though generally rising also, rose in less
degree than the all-age rate; and when the all-age rate was falling, the rate at ages 3-10
years fell in even greater degree than the all-age rate.
(2) That in 1871-80 with a general decline of the diphtheria mortality at all ages in the
several groups of population, there occurred in each group at ages 3-10 years a relatively
higher diphtheria death rate than before, that is, the diphtheria mortality, at ages 3-10 years
did not fall in 1871-80 in anything like the same degree as the diphtheria mortality at all
ages.
This new departure is most noticeable in London, and least noticeable in the rural groups. The
special incidence upon the age 3-10 years in England and Wales and London is maintained in 1881-90
as compared with 1855-60 and 1861-70, but the material is not yet available for determining whether
this special incidence is maintained in the other groups. If the London death rates of 1891-3 are
compared with those of 1855-60, it is found that in 1891-3 while the all-age death rate had increased
313 per cent., that at the ages 3-10 years had increased 457 per cent., and again if compared with the
death rates of 1861-70 it is found that in 1891-3 the all-age death rate had increased 196 per cent.,
and that at the ages 3-10 years had increased 309 per cent.
It is important to determine as accurately as possible the year in the periods 1861-70 and 1871-80
in which the special incidence upon the ages 3-10 years was first manifested, and an examination
of the statistics of each year shows that in the year 1871, the year following that in which the
Elementary Education Act first came into operation, there was a notable increase of incidence of
diphtheria mortality in the age period 3-10 years, which has been maintained ever since, and which
has in later years been much accentuated.
In view of the change in the age incidence of diphtheria mortality which has been referred to, it
is desirable that diagrams illustrating the number of cases notified in each week in the years 1892 and
1893 should be studied as in the case of scarlet fever. Diagrams XII. and XIII. have therefore been
prepared for this purpose.
It is unnecessary to repeat here the observations on the subject of school influence which have
already been made in discussing the decrease of scarlet fever in the month of August. It may however
be pointed out that the August depression in the all-age diphtheria curve of 1892 is not
obvious, but that of 1893 is distinct, and is especially conspicuous in the curve relating to children y
from 3-13 years of age.

The following table shows the age distribution of the cases notified and the fatality at the several
ages of this disease. It will be seen that the incidence of attacks was greater on females than males
and of deaths on males than females; the greatest incidence of disease was in both sexes in 1893 on
children three to four years of age, but the greatest incidence of death was on children one to two years
of age. The fatality (case mortality) of males was greater than the fatality of females; the highest
fatality of the males occurred among those who were under one year of age, and of females among those
who were from one to two years of age. A further point of some interest is that while at 'all ages'
females suffered more than males from diphtheria, during each of the first four years of life they suffered