G. D. Maynard 
289 
There seems to be no doubt that in America there is a negative correlation 
between cancer and better social class, as measured by occupation, while there is a 
high positive correlation between diabetes and better social conditions. Tims 
Cancer and Occupation. 
Dea,th-rate. 
Diabetes and Occupation. 
Death-rate. 
H. L. 
H. L. 
Social 
Status 
[High 
I Low 
2 
7 
9 
5 
12 
17 
11 
8 
19 
8 
3 
11 
13 
15 
28 
13 
15 
28 
Social I 
Status I 
High 
I Low 
r=--56 + 09, r: 
•63 + -08. 
H. 
L. 
H. 
L. 
9 
0 
9 
11 
6 
17 
3 
16 
19 
1 
10 
11 
12 
16 
28 
12 
16 
28 
r 
= 10, 
r = -82 + 
•04. 
there does not seem any reason for supposing that an artificial correlation will 
have arisen between cancer and diabetes death-rates owing to prevalence of 
varying occupations in the different cities. 
If the increased rates observed in the cases of cancer and diabetes were due to 
a common cause then it is pi'obable that their rates of growth will be found to be 
fairly highly correlated. Not being able to obtain rates for a sufficient period of 
time, from the United States reports, the rates given in the Registrar's Report for 
England and Wales, in five-yearly groups, for the 85 years 1871 to 1905 were used, 
and here p = "8060 + •0893. This high correlation shows I think a strong proba- 
bility that there is a common factor influencing the increase of both diseases. 
That this value is explicable on the assumption that the increased rates are 
merely apparent and due to more careful diagnosis is in view of the facts already 
mentioned almost inconceivable. It is equally clear that the increase is not due 
to alteration in the age constitution of the population. For example had the same 
cancer death-rate been operating in 1851 — 60 as was so acting from 1S91 — 00 the 
death-rate would have been 743 per million, and in 1871—80, 749, while in 1891 — 00 
it was 758. Thus in 50 years the increased ratio of old people would have led to 
a gain in rate of only 15 deaths per million of the population, whereas the recorded 
increase in the last 35 years 1871 — 05 is 534 per million. It has been previously 
pointed out, that no great increase in our knowledge of either disease has recently 
been made, that would aid the general practitioner in more accurate diagnosis in 
the final stages of the disease. 
If then we have succeeded in excluding artificial sources of correlation, it 
remains to find, if possible, the factor that is producing the increasing rates in 
these two diseases, and giving rise to their correlatiun in the various cities and 
districts. 
Only one cause, it seems to me, will fit the facts as we know them, viz. : the 
pressure of modern civilisation and the strain of modei-n competition, or some 
