Malaria saved the lives of thousands of workers and helped develop the methods used in future public-health campaigns against the disease. The first effective treatment for malaria came from the bark of cinchona tree, which contains quinine. This tree grows on the slopes of the Andes, mainly in Peru. The indigenous peoples of Peru made a tincture of cinchona to control fever. Its effectiveness against malaria was found and the Jesuits introduced the treatment to Europe around 1640; by 1677, it was included in the London Pharmacopoeia as an antimalarial treatment. It was not until 1820 that the active ingredient, quinine,
Jesuit's bark of the long list of brochures defending its use and the only independent article on this bark which has been issued by a Jesuit. The two Genoese, Girolamo Bardi, a priest, and Sebastiano Baldo, a physician, who were among the pioneer advocates of the plant, were intimate with the cardinal, and Baldo prefixed to his principal work a letter from de Lugo, dated 1659, on cinchona, which shows that the cardinal even when seventy-seven years old was still active in its behalf. Circumstances created a suitable opportunity for disseminating the bark from Rome throughout Europe by means of the Jesuits.