ON THE COERELATION BETWEEN VACCINATION 
AND SMALLPOX IN THE LONDON EPIDEMIC, 1901-2. 
By F. M. turner, M.D. 
At the suggestion of Prof. Pearson I have undertaken the calculation of the 
smallpox statistics of the Metropolitan Asylums Boai'd Hospitals for the epidemic 
of 1901-2, in continuation of the two papers already published on the same subject 
by Macdonell in this Journal ; and the results are given in this paper. I also 
include a discussion of several points, which have occurred to me in the course of 
the calculations, which seem to me to have considerable importance in altering 
the values of the coefficients. Of these the most important is a suggestion as to 
the probable frequency distribution of severity among smallpox cases, which I call 
a "curtailed" normal distribution, and a discussion is given of the mathematical 
formulae appropriate to such a distribution. All the data were obtained from 
the Annual Reports of the Metropolitan Asylums Board for the years 1901 and 
1902. 
Taking a fourfold division into vaccinated and unvaccinated and into recoveries 
and deaths, as in the above-mentioned papers, we get the following tables for the 
calculation of r. They only differ in the treatment adopted for the doubtful cases, 
which in Table I. are classed with the vaccinated, in Table III. with the unvac- 
cinated, and in Table II. have been omitted altogether. 
TABLE I. 
All Gases, 1901 — 2. Vaccination and Severity. 
Recoveries 
Deaths 
Totals 
Unvaccinated 
1525 
753 
2278 
Vaccinated or doubtful . . . 
6505 
876 
7381 
Totals 
8030 
1629 
9659 
r= --4246 ±-0049. 
