Dutch doctor (1860–1927) who invented the first practical electrocardiogram, receiving the Nobel Prize for Medicine in 1924. Uncommon ink signature, “With best wishes for your collection, W. Einthoven, Leiden, March 12, 1926,” on an off-white 5.5 x 3.5 postcard. In fine condition, with light show-through from postmarks above first line of sentiment. RR Auction COA.
