ABSTRACT
A HISTORICAL PERSPECTIVE OF HEMODIALYSIS The foundation of the science of dialysis-the knowledge on which it is basedwas laid by the Scottish scientist Thomas Graham, who coined the term dialysis (1). Graham used this word to describe a phenomenon he observed-that of the separation of crystalloids from colloids by passage through a semipermeable membrane composed of albumin-covered parchment. In 1854 he predicted that his findings relating to osmosis and semipermeable membranes could be applied to medicine. Such applications were indeed attempted by many clinicians in the decades that followed. Although hemodialysis did not become a viable clinical tool for the treatment of renal failure until the 1960s, the first clinical dialysis was performed on animals by the German physician George Haas in 1914. His research in dialysis continued and, in October 1924, he was credited with the first dialysis on a clinically uremic human (2). With the help of an understanding of the basic physical principles of dialysis, the early pioneers were able to meet the challenges of producing semipermeable membranes across which blood could be purified and of developing an extracorporeal system through which the blood could circulate without clotting. Thereafter, the research revolved around elabo-
rating the physics of dialysis as well as improving the dialysis membrane. Dialysis machines were constantly being improved, with particular attention to safety of the dialysis procedure.
