The kidneys perform the vital function of filtering waste materials out of the blood. When the kidneys stop functioning, death due to waste buildup occurs quickly. As early as 1861 a Scottish chemist, Thomas Graham (1748-1843), described a procedure he called dialysis to purify the blood in cases of kidney failure. The blood would be diffused across a membrane that allowed wastes to pass into a balanced fluid, while replenishing substances would pass from the fluid into the blood. Practical application of dialysis was developed by John Jacob Abel, the first professor of pharmacology at Johns Hopkins University School of Medicine. In 1912 Abel was investigating byproducts in the blood, and needed a device to filter these substances out. With colleagues Benjamin Turner and Leonard Rowntree, he built a machine that circulated blood through celloidin tubing immersed in a saline-dextrose solution and wrapped around a rotating drum. Urea...