The theory that the extreme elevation of the temperature during July, August and September is the direct cause of summer diarrhea was very popular with the early American physicians. Booker1 has given us an interesting history of the subject. Diarrhea in infancy as a summer disease was not recognized in Europe until recent times, but was accurately described by Benjamin Rush of Philadelphia in 1777. To this physician is also credited the theory that heat is the principal factor in the causation of the disease, but a careful reading of his article shows that he was inclined to view the disease as a modification of malaria. It was really Dr. E. Hornell of Philadelphia in 1823 who first clearly expressed the direct connection between heat and cholera infantum. He wrote:
Whatever consideration attaches to irregularities in diet, inattention to cleanliness, difficulty of dentition, etc., I am disposed to consider