MITCHELL, John, physician, born in England; died there in March, 1768. He studied medicine and came to this country about 1700, settling in Urbana, near Richmond, Virginia Dr. Mitchell acquired considerable reputation by his researches in bet-any, and gave much valuable information on American flora to Linnaeus, who bestowed Mitchell's name on the " Mitchella repens." Among his researches in this science are "Dissertatio brevis de Principle Botanicorum et Zoologorum," dedicated to Sir Hans Sloane, and dated Virginia, , 1738, and " Nova Plantarum Genera," dedicated to Peter Collinson (1741). These were afterward collected and published (Nuremberg, 1769). Mitchell was a fellow of the Royal society and contributed to this " Transactions .... Essay on the Causes of Different Colors of People in Different Climates," in which he argues that influence of climates and modes of life are sufficient to account for differences of color (1744); " Essay on the Preparations and Uses of Various Kinds of Potash" (1748); and " Letter Concerning the Force of Electrical Cohesion." Among his manuscript papers was one on the "Yellow Fever in Virginia in 1737-'42," with correspondence with Benjamin Franklin, which was published, with additional papers on this subject, by Dr. Benjamin Rush in the fourth volume of the "American Medical and Philosophical Register" (1755). He is also credited with the authorship of "A Map of the British and French Dominions in North America" (London, 1755); "The Contest in America between Great Britain mid France " (anonymous, about 1757); and "The I)resent State of Great Britain and North America" (1767).