Diagram showing the relation between the death-rate from small-pox and the proportion of population protected by
vaccination in each district of the United Provinces.

[NLS note: a graphic appears here - see image of page]

The black lines and figures indicate proportion of population protected by vaccination during the year 1922-1923 and the six years preceding it.
The red lines & figures indicate the death-rate from small-pox during 1922.