Researches with the Dropping Mercury Cathode. Part II. The Polarograph; Reprinted from Recueil des Travaux Chimiques des Pays-Bas, Vol. 46, No. 5, pp. 496–498

Harleem: Société chimique néerlandaise, 1925. First Edition. Offprint, 8vo (236 × 157mm), pp. 3, plus 4 inserted plates. From the Physico-chemical Institute of the Charles University, Prague. Original green printed wrappers, staple-bound, light toning and a couple of small spots to the rear wrapper, else near fine. Signed by Heyrovský on the front wrapper. Heyrovský received the Nobel Prize in Chemistry in 1959 for his discovery and development of polarography, the electroanalytical method he had introduced at Charles University in Prague in the early 1920s. Polarography rests on the behavior of the dropping mercury electrode: as mercury falls in regular drops from a fine capillary into an electrolyte solution, the resulting current-voltage relationship traces a characteristic stepped curve whose half-wave potential identifies the electroactive species present and whose limiting current measures its concentration. The method was the first to permit simultaneous qualitative and quantitative analysis of multiple substances in solution at trace concentrations. The electrochemical sensing principle it established (measuring concentration from a limiting current at a known electrode potential) is the direct ancestor of the amperometric biosensor, and by extension of the enzyme electrode used in the home blood glucose meter, now one of the most widely deployed diagnostic devices in the world. The offprint offered here is the paper in which Heyrovský and Shikata introduced the polarograph, the automated instrument that made the method practically viable and whose construction is here described and named for the first time.