286 
A Statistical Study in Cancer Death-Hates 
and diseases of "ill-defined or uncertain cause." Probably one of the most suit- 
able diseases as a control would be nephritis, were it not that its age frequency 
is so similar to cancer, thus the age factor will give rise to errors to an even 
greater extent than occurs in the case of diabetes. 
Ore: 
I 
^1 Mont 
oaho 
5m "^'"''^^ 
N. DAK \ 
- ; MINN / 
S. DAK ^ • ' 
w 
lOWi 
NEBR 1 
) ARIZ 
OK LA ,-' 
MO •> 
OHIO 
— S.C. 
> 
DA \ 
1 ^^^ Eegistration States, 1900. 
„ added, 1906. 
• Eegistration Cities dealt with in this paper. 
Fig. 3. 
The values of p and p' are given for this disease as they may serve as a useful 
contrast to the other correlation values. In calculating the value of p' the cancer 
correction factor was used for the nephritis deaths as the age frequencies of the two 
diseases are not very dissimilar. Cancer and Nephritis, 40 Cities : 
p = -3792 + -0913, p' = -1571 ± -1040. 
These values are of a quite different order fi'om those found for cancer and 
diabetes, 
