It was really a colossal task in itself to undertake the cleaning of the city of Panama, which had been for centuries a pest-house, the mortality in which, even after the American occupation, reached during one month the rate of 71 per thousand living.

There have been a great many brilliant illustrations of the practical application of science in preserving the health of a community and in saving life, but it is safe to say that, considering the circumstances, the past history, and the extraordinary difficulties to be overcome, the work accomplished by the Isthmian Canal Commission is unique.

The year 1905 was devoted to organization; yellow fever was got rid of, and at the end of the year the total mortality among the whites had fallen to 8 per thousand, but among the blacks it was still high, 44.

For three years, with a progressively increasing staff which had risen to above 40,000, of whom more than 12,000 were white, the death rate progressively fell.
Of the six important tropical diseases, plague, which reached the Isthmus one year, was quickly held in check.

Yellow fever, the most dreaded of them all, never recurred.