De' fenomeni della circolazione osservata nel giro universale de' vasi: de' fenomeni della circolazione languente; de' moti del sangue independenti dall' azione del cuore; e del pulsar delle arterie

Lazzaro Spallanzani was a Jesuit priest, biologist and physiologist. He was one of the first to disprove the theory of spontaneous generation, yet also investigated the ability of various animals to regenerate missing body parts. He proved that microorganisms could be killed with intense heat. In Dell'azione del cuore ne' vasi sanguini Spallanzani outlined his findings on the action of the heart upon the blood vessels. He demonstrated the rhythmic inequality of blood flow in the aorta and large vessels disappeared in medium and small arteries, becoming regular and uniform. The blood velocity in the venous system increased as the caliber of the vessels enlarged. Spallanzani dedicated this treatise to Albrecht von Haller.