Licence: Public Domain Mark
Credit: Diphtheria: its natural history and prevention. Source: Wellcome Collection.
Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.
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![It has been very generally held, and I believe with truth, that the broad geological features of a district have no known influence on the development or the diffusion of diphtheria. Any one who will 'recall the main features of England and Wales as ordinarily shown on a geological map, will find in the chart prepared by l)r. Longstaff,^ and which shows by different degrees of shading the average diphtheria death-rates in the regis- tration counties of England and Wales for the twenty-six years 1855-80, abundant material in support of this view. Dr. Longstaff takes 100 as representing the average diphtheria death-rate for England and Wales as a whole, and he then proceeds to divide the counties into five groups according as they fall short of or exceed that average rate. We thus learn that during the period in question the greatest excess of fatal diphtheria took place in Lincolnshire, Norfolk, Sussex, and North Yorks, the rates ranging from 149 to 191. In Lincolnshire (rate 191), w^here the geological con- ditions are by no means uniform, the upper and lower cretaceous, with thick drift covering of boulder clay, and the oolitic beds, together with the great level of the fen, practically make up the county. Cambridgeshire and Huntingdonshire taken together (rate 119) may be regarded as affording sufficient geological comparison with Lincolnshire, and yet the difference between their respective rates amounted to no less than 72. There is ^ Chart from Studies in Statistics, by G. B. Longstaff, ]M.A., M.B., Oxon. London, Edward Stanford, 1891—reproduced by the author's permission. C](https://iiif.wellcomecollection.org/image/b21205814_0031.jp2/full/800%2C/0/default.jpg)
