James Carroll: a biography

James Carroll was born in England in 1854; at the age of 15, he emigrated to Canada where he worked at various odd jobs. At age 20, he crossed the border and volunteered for the US Army, in which he remained for the rest of his life. Appointed as Hospital Steward, he became interested in medicine. He was permitted to take basic courses at St Paul University and later at Bellevue Hospital in New York. He received his MD degree in 1891 from the University of Maryland while still a sergeant. He then took the course in bacteriology offered by Welch at Hopkins. At an 1893 international exposition in Chicago, Carroll was put in charge of the Army's exhibit on bacteriology. He was then called to become Assistant Professor of Microscopy at the new Army Medical School; his senior there was Walter Reed. Both men were offered professorships in pathology and bacteriology at George Washington University, and in 1900, both were appointed to the US Board sent to Havana. After several weeks, the Board determined that the alleged agent causing yellow fever was Bacillus cholerae suis (Sanarelli). Visiting British researchers informed the Board of their favorable view of Carlos Finlay's theory that the disease was transmitted by the mosquito. The Board then visited Finlay, who gave them eggs of the particular species of mosquito that he had discovered to be the culprit. Board members Lazear and Carroll submitted themselves to the bite of an infected mosquito; both developed severe fever and Lazear died. The Board then carried out a well-planned experiment which proved that Finlay had been right for 20 years. Further experiments by Carroll showed that the agent could pass through a Berkefeld filter and was not bacterial.