From this it appears that adventitious deafness is increasing in relation to total deafness, which is most likely the case, as congenital deafness, as we shall see, is evidently decreasing. Whether or not adventitious deafness is increasing in respect to the general population, the table 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 in order.