Marcello Malpighi Biography (1628-1694)
In the second half of the seventeenth century, Marcello Malpighi used the newly invented microscope to make a number of important discoveries about livingtissues and structures, earning himself enduring recognition as a founder ofscientific microscopy, histology (the study of tissues), embryology, and thescience of plant anatomy.
Malpighi was born at Crevalcore, just outside Bologna, Italy, on March 10, 1628. The son of small landowners, Malpighi studied medicine and philosophy atthe University of Bologna. While at Bologna, Malpighi was part of a small anatomical society headed by the teacher Bartolomeo Massari, in whose home the group met to conduct dissections and vivisections. Malpighi later married Massari's sister.
In 1655, Malpighi became a lecturer in logic at the University of Bologna; in1656, he assumed the chair of theoretical medicine at the University of Pisa; in 1659, he returned to Bologna as lecturer in theoretical, then practical,medicine; from 1662 to 1666, he held the principal chair in medicine at theUniversity of Messina; finally in 1666, he returned again to Bologna, where he remained for the rest of his teaching and research career. In 1691, at theage of sixty-three, Malpighi was called by his friend Pope Innocent XII to serve as the pontiff's personal physician. Reluctantly, Malpighi agreed and moved to Rome, where he died on November 29, 1694, in his room in the Quirinal Palace.
Early in his medical career, Malpighi became absorbed in using the microscopeto study a wide range of living tissue--animal, insect, and plant. At the time, this was an entirely new field of scientific investigation. Malpighi soonmade a profoundly important discovery. Microscopically examining a frog's lungs, he was able for the first time to describe the lung's structure accurately--thin air sacs surrounded by a network of tiny blood vessels. This explained how air (oxygen) is able to diffuse into the blood vessels, a key to understanding the process of respiration. It also provided the one missing piece of evidence to confirm William Harvey's revolutionary theory of the blood circulation: Malpighi had discovered the capillaries, the microscopic connectinglink between the veins and arteries that Harvey--with no microscope available--had only been able to postulate. Malpighi published his findings about thelungs in 1661.
Malpighi used the microscope to make an impressive number of other importantobservations, all "firsts." He observed a "host of red atoms" in the blood--the red blood corpuscles. He described the papillae of the tongue and skin--the receptors of the senses of taste and touch. He identified the rete mucosum,the Malpighian layer, of the skin. He found that the nerves and spinal column both consisted of bundles of fibers. He clearly described the structure ofthe kidney and suggested its function as a urine producer. He identified thespleen as an organ, not a gland; structures in both the kidney and spleen arenamed after him. He demonstrated that bile is secreted in the liver, not thegall bladder. In showing bile to be a uniform color, he disproved a 2,000-year-old idea that the bile was yellow and black. He described glandular adenopathy, a syndrome rediscovered by Thomas Hodgkin (1798-1866) and given that man's name 200 years later.
As if this catalog of human-tissue discovery weren't enough, Malpighi also conducted groundbreaking research in plant and insect microscopy. His extensivestudies of the silkworm were the first full examination of insect structure.His detailed observations of chick embryos laid the foundation for microscopic embryology. His botanical investigations established the science of plantanatomy. The amazing variety of Malpighi's microscopic discoveries piqued theinterest of countless other researchers and firmly established microscopy asa science.