o the disease which have
significance. We have already seen that in a given country there is a
kind of uniformity in the number of those dying from the disease from
year to year; but another phenomenon relates to the unequal pressure
in difference countries of the causes of the disease.

1. THE DEATH-RATE FROM CANCER APPEARS GREATLY TO VARY ACCORDING TO
RACE AND ENVIRONMENT.

CANCER DEATH-RATE IN DIFFERENT COUNTRIES PER 100,000 POPULATION

---------------------------------------------------------------
| Five-Year Periods. | Switzerland. | England. | Italy. |
|--------------------------|--------------|----------|--------|
| 1886-1890 .. .. | 114 | 63 | 43 |
| 1891-1895 .. .. | 122 | 71 | 44 |
| 1896-1900 .. .. | 127 | 80 | 51 |
| 1901-1905 .. .. | 128 | 87 | 55 |
---------------------------------------------------------------

Here is the record of a period of twenty years. These differences of
proclivity to cancer are exceedingly curious. Can the reader perceive
why they exist?

The rate in England is quite 50 per cent. higher than that of Italy.
If we explain this by the hypothesis of greater skill in detecting the
disease, what are we to say of the cancer-rate in Switzerland, which
is 50 per cent. higher than that of England?

But here is another curious fact. The United States census of 1900
permits a contrast of the mortality of cancer according to the
birthplaces of mothers of those attacked. Here, for instance, is the
death-rate from cancer and tumour of persons of different nationality,
calculated in three sections of the country--the rural districts of
the registration area, the cities of the same section, and the cities
outside the registration area.

DEATH-RATES IN THE UNITED STATES FROM CANCER AND TUMOUR PER 100,000
WHITE POPULATION, ACCORDING TO THE BIRTHPLACE OF THE MOTHERS OF
PATIENTS

---------------------------------------------------------------
| | | |
| | Registration Area. | Other |
| COUNTRIES. |----------------------| Cities. |
| | Rural | Cities. | |
| | Districts. | | |
|--------------------------|------------|---------|-----------|
| Italy .. .. .