Diphtheria Death-rates per million, according to density of population.

Period Dense Medium Sparse
1855-60 123 182 248
1861-70 163 164 223
1871-80 114 125 132

In Scotland, also, the incidence was the same: e.g. in 1862, of 997 deaths, 360 were in the towns, 617 in the mainland rural and 20 in the insular districts[1375].

The law of incidence of diphtheria upon town and country respectively has become a good deal confused by the extraordinary severity with which diphtheria has fallen in the last two or three years upon most parts of London and upon the adjoining municipal boroughs of Croydon and West Ham. The following table compares the annual death-rates per million in all England and Wales and in London from the year of the first recognition of diphtheria to the present time.

Death-rates from Diphtheria per million, in all England and in London.

Year England London
1855 20
1856 32
1857 82
1858 339
1859 517 284
1860 261 174
1861 225 239
1862 241 288
1863 315 275
1864 261 207
1865 126 144
1866 140 152
1867 120 145
1868 137 155
1869 47 107
1870 120 104
1871 111 105
1872 93 80
1873 108 95
1874 150 122
1875 142 167
1876 129 109
1877 111 88
1878 140 155
1879 120 155
1880 109 144
1881 121 171
1882 151 220
1883 158 241
1884 185 236
1885 163 221
1886 147 205
1887 157 226
1888 168 305
1889 185 371
1890 179 330
1891 173 340
1892 222 460
1893 302 740

The deaths in London in 1893 were 3196, having been 1962 the year before, but never more than half the latter total in any year previous to 1888. Besides Croydon and West Ham, Cardiff is the great town which has come nearest the London rate, having had O·68 deaths from diphtheria per 1000 living in 1892, while Swansea had only 0·05, Wolverhampton (including Bilston and Willenhall) only 0·06, Huddersfield 0·03 and Blackburn 0·02. In London the very high death-rate of 1893 was distributed not unequally over all the divisions, the highest mortality corresponding to the highest fecundity.

Diphtheria in London in 1893.

District Death-rate
from all causes
Birth-rate Diphtheria
death-rate
Eastern 25·1 37·3 1·00
Central 26·6 29·0 0·82
Southern 19·9 31·7 0·73
Northern 20·0 29·3 0·73
Western 18·7 26·4 0·52

Diphtheria shows no such decided preference for the late autumnal or early winter season as scarlatina, but the winter is on the whole its most fatal season, according to the following annual averages of the quarters of the year for twenty years from 1870 to 1889 (total of 67,676 deaths in England and Wales).