134 REPORT OF THE LEPROSY COMMISSION:
vaccine lymph down from British Garhwal, a markedly leprous
district, and using it for vaccinating in that part of the plains
included between the rivers Ganges and Jumna. Now, the first
census returns (1867-72) show that, whereas the proportion of
lepers in British Garhwal was 24·0 per ten thousand, that in the
plains between the rivers was only 2·25 to 2·5 per ten thousand.
Here, then, is an approximation to a scientific experiment.
Children in a district where leprosy is comparatively rare are
vaccinated with lymph from a district where leprosy is many
times more common. If vaccination were responsible for
spreading leprosy, an increase of the disease in this particular
part of India might justly be expected.
As a matter of fact, however, on comparing the census
returns for the districts in question, the following will be found
to be the facts:-
British Garhwal.					District between the Ganges 
								and Jumna.
1867-72   	. 	24·0 per 10,000		2·25 to 2·5 per 10,000
1881        .   	18·1  per 10,000		2 25 to 2·5 per 10,000
1891        . 	16·9 per 10,000		1·5 to 2·0 per 10,000
Thus not only has leprosy fallen in British Garhwal from
24.0 to 16.9 per ten thousand, but in the district vaccinated with
lymph from British Garhwal the proportion of lepers has
remained stationary, if not decreased.
As Dr. Pringle was on duty, as stated above, from 1864
to 1884, and the number vaccinated with his lymph was
gradually accumulating all these years, even allowing for
removal by death and other counteracting influences, such as
the diminution of leprosy in British Garhwal, it should be
expected that by 1881 and 1891 the figures would show some
evidence of the increase of leprosy which is alleged to follow
the use of lymph collected in leprous districts. This increase,
however, does not appear in the census returns.
In conclusion, those who accuse vaccination of spreading
leprosy must first ensure the correctness of their major premise