The beginnings and development of the electrocardiograph.

In 1791, Galvani, in Italy, first showed electromotor activity in the leg muscle of the frog (1). Action potentials of skeletal muscle were later found by several physiologists in the 19th century and in the 1870s, electromotor phenomena were found in heart muscle using exposed animal hearts. Lippman in Paris, in 1872, invented the capillary electrometer which could demonstrate cardiac electrical activity without having to expose the heart (2). This sensitive but sluggish apparatus consisted of sulphuric acid and mercury in a capillary tube with wires at each end (Fig. 1). Movements of the meniscus Augustus Volnay who had described nerve degeneration. The electrogram, as he called it, was recorded from a light beam on the mercury meniscus aimed at a slowly moving toy train carrying photographic plates (Fig. 2). Waller’s dog Jimmy, (Fig. 3), standing in saline jars was his collaborator MEDICAL HISTORY