One of the most dramatic examples of the effect of advances in medical knowledge is the building of the Panama Canal.
In 1881, work was started on this canal under the supervision of DeLesseps, the Frenchman who built the Suez Canal.
The project had to be abandoned after mosquito-borne diseases of yellow fever and malaria had claimed 16,000 victims among the workers.
At the beginning of this century, the area was made healthy by spraying the breeding waters of the mosquitoes with petroleum.
Work was able to be started again and the canal was finished in 1914.