Vierordt invented a sphygmograph which acted on the principle that indirect estimation of blood-pressure could be accomplished by measuring the counter-pressure necessary to obliterate the arterial pulsation. This was the first instrument with which a tracing of the human pulse could be made. The paper is the first record of a study with an instrument of precision of the pulse in health and disease. Vierordt expanded this work into book form: Die Lehre von Arterienpuls, Braunschweig, Vieweg, 1855.