Dr. John P. Merrill (left) explains the workings of a then-new machine called an artificial kidney to Richard Herrick (middle) and his brother Ronald (right). The Herrick twin brothers were the subjects of the world's first successful kidney transplant, Ronald being the donor.
John Putnam Merrill (March 10, 1917 – April 14, 1984) was an American physician and medical researcher. He led the team which performed the world's first successful kidney transplant.[1] He generally credited as the "father of nephrology"[2] or "the founder of nephrology," which is the scientific study of the kidney and its diseases.[1]