Alphonse Laveran was a French army physician who took advantage of his period of service in Algeria to study malaria, a disease known since ancient times and common in tropical and subtropical areas. Using very primitive technology, he discovered and ultimately proved that malaria was caused by a minute animal parasite; he also suggested, though he did not himself prove, that the parasite was transmitted to human beings by some species of mosquito. He later went on to study other diseases caused by parasites. For the work he did in this field throughout his career, he was awarded the Nobel Prize in medicine in 1907.

Charles Louis Alphonse Laveran was born on June 18, 1845, into a military family in Paris. He was the second child and only son of Louis-Theodore Laveran, a career military physician, and Marie-Louise Anselme Guénard de la Tour Laveran. When Laveran was five years...