American pathologist who performed a primary position withinside the creation of current scientific exercise to the U.S. As the primary dean of the scientific faculty at Johns Hopkins University (1893-98), Welch revolutionized American medication through worrying of its college students a rigorous observe of bodily sciences and an lively involvement in scientific obligations and laboratory work. His college students protected Walter Reed, James Carroll and Simon Flexner. As an authentic investigator, With Flexner, he demonstrated (1891-92) the pathological outcomes produced through diphtheria toxin. In 1892, he observed Micrococcus albus and its relation to wound fever and of Clostridium welchii (Welch’s bacillus), the causative agent of fueloline gangreane. Died 30 Apr 1934 at age 84 (born 8 Apr 1850).