On a method of isolating the mammalian heart.

Martin devised a form of perfusion of the isolated mammalian heart – one of the greatest single contributions ever to come from an American physiological laboratory. This made possible his later work on the heart. See W. Bruce Fye,  "H. Newell Martin and the isolated heart preparation: The link between the frog and open heart surgery," Circulation , 73 (1986) 857-864.
Also in 1881 Martin published a different account: "A new method of studying the mammalian heart," Studies from the Biological Laboratory, 2 (1881) 119-130, with an engraved plate drawn by Martin.