For those engaged in military conflict at the end of the nineteenth century, infection and disease were still as formidable enemies as the guns of an opposing army. Yet advances in sanitary science and understanding continued to help officers keep their troops in optimal fighting condition. After serving as an assistant surgeon for the Union Army during the American Civil War, Alfred Alexander Woodhull (1837-1921) began to publish on the topics of hygiene and sanitation, and how they related to military effectiveness. Arguably his most important publication, the present work was based on lectures he delivered at the US Infantry and Cavalry School. It covers such varied topics as the selection of men, uniform design, and the management of waste. First published in 1890, it was recommended as a textbook by the surgeon general of the time. Reissued here is the revised third edition, which appeared in 1904.