e does not disclose definitely. The statistics
probably are not full enough to afford any real indication yet.

Our next inquiry is in respect to the increase or decrease of
adventitious deafness from the several diseases individually, which is,
upon the whole, the more satisfactory test. Here also, unfortunately,
our statistics are very limited, and our findings will have to fall much
short of what could be desired.

The following table, based on the returns of the censuses of 1880, 1890
and 1900, so far as the approximate identity of the several diseases can
be established, will give the respective percentages found.[32]

CAUSES OF ADVENTITIOUS DEAFNESS IN 1880, 1890 AND 1900

1880 1890 1900

Scarlet fever 7.9 11.8 11.1
Meningitis 8.4 7.8 9.6
Catarrh and catarrhal fevers 0.9 3.3 3.6[33]
Diphtheria 0.2 0.5 --[34]
Abscess and inflammation 1.0 2.5 --[35]
Measles 1.3 2.5 2.5
Whooping cough 0.5 0.8 --[34]
Malarial and typhoid fevers 1.7 1.8 3.6
Other fevers 1.1 -- 2.0

In this table the most noticeable thing is perhaps the persistency with
which we find most of the diseases to recur, with apparently no great
change, while in certain ones, as catarrh and malarial and typhoid
fevers, there seems to be rather an increase. It would be best, however,
not to place very great confidence in these figures, but, so far as the
census reports are concerned, to wait for more precise and uniform
statistics.

We have, further, the statistics published in the reports of certain
schools for the deaf. While these are perhaps not of sufficient extent
to warrant full conclusions, they may be regarded as quite
representative;[36] and though to be taken with something of the caution
as the census figures, they may serve to throw some light upon the
situation. Comparison of the proportions of pupils deaf from the several
diseases at different times may be made in two ways: by finding the
respective proportions over a series of successive years from a certain
time back down to the present, and by contrasting the proportions in two
widely separated periods, one in the present and one in the past. These
will be taken up i