Malpighi and discovery of capillaries
Marcello Malpighi, was born in Italy in the year 1628. It was the same year, when an English Physician William Harvey had discovered circulation of blood. Blood flows out from heart through the arteries, Harvey discovered and is returned back to it by veins. What connects arteries and veins was yet to be discovered. While Malpighi completed his medical education in 1653, and became a faculty of medicine three years later at University of Bologna in Italy, connection between an artery and vein remained a mystery.
Malpighi’s parents and grand-parents passed away when he was still in medical school. His wife also died within a year of his marriage. Later his brother was murdered, and these personal losses took their toll. Meanwhile, Malpighi moved from Bologna to a newly formed University of Pisa.
Incidentally, Pisa was birth place of Galileo, a famous astronomer and inventor of telescope. Galileo born in 1564, lived on till age of 77. Way back in 1609, when Galileo made his telescope, he had also invented a compound microscope. This instrument could magnify objects upto 30 times of its size. Just reverse of a telescope, Galileo did not put it to much of an use. Rather, he was interested in telescope and newly discovered astronomical; facts. Somewhere this compound microscope was left behind.
Malpighi puts microscope to use
In 1661, Malpighi made his groundbreaking discovery. He started looking at various tissues, under the Galileo’s compound microscope. He identified small vessels that were previously never seen by a naked eye. These were capillaries, the elusive connection between arteries and veins. These thin hair like structures were named so, as capillus in Latin means hair. This discovery was first made in a frog’s lung. Hence, this was also the first time, we were able to understand pulmonary circulation and gas exchange through the capillaries.
Meanwhile over next six years, Malpighi moved from Pisa to Bologna, then to Sicily and back to Bologna. Back, where he started from, he started look at various other animal organs. He was the first to describe glomeruli in Kidney as well as lymphatic bodies in spleen. (both called Malpighian Corpuscles). There are many other microscopic structures that bear his name. He saw and also drew growth of organs in a chick embryo in quite detail. Thus Malpighi became a pioneer in microscopic anatomy. H had his critics and it took a while for all to realize worth of his work.
Antonio Vallisneri and work on insects
Antonio Vallisneri (1661-1730) was a Malpighi’s student at Bologna. However, he was more drawn towards Giovanni Girolamo Sbaraglia, another faculty member and a critic of Malpighi. He got interested in insects, and devoted himself passionately to entomological research. The first result of these interests were the Dialogues on the curious origin of several insects, which made him quite popular. He was a prolific writer, and an ardent supported of scientific thought. His contributions range from medicine, and biology to natural sciences and even geology.
By the time Antonio Vallisneri was looking at insects with his compound microscope, the instrument was also undergoing a change. The Huntley microscope, manufactured in London around 1740, is a historical example of a single-lens microscope. Another historic microscope was a 1751 Instrument, created by Alexis Magny. This microscope featured a point micrometer, had a rack and three set of lenses, along with a light condenser. As the resolution of microscope improved, so did the structures and organisms that could be seen under it.
Spallanzani and rejection of theory of spontaneous generation
Lazzaro Spallanzani was born in 1729, just a year before Antonio Vallisneri had died. Funded by Vallisneri foundation, Spallanzani first studied theology and then law. In university of Bologna, he developed a friendship with Antonio Vallisnieri’s son, Antonio Vallisnieri Jr. He convinced Spallanzani’s father to agree for a career in science and academics.
In 1765, Spallanzani refuted the theory of spontaneous generation. His studies using microscopic techniques proved that microorganisms in atmosphere, multiply and colonize, rather than being generated de-novo from rotten food. This work preceded that of Louis Pasteur by about a century.
He also used microscopy techniques to demonstrate reproduction, and process of digestion. His other work includes descriptions of geology, principles of physics, literature and animal acoustic physiology.
Agostino Bassi shows that microbes cause disease
Like Spallanzani, Agostino Bassi also had a passion for biology. He was a student to Spallanzani at university of Pavia, in Italy. In 1798 he completed law, but was also taking courses in physiology and biology at the same time. Spallanzani’s rejection of theory of spontaneous generation did impact his future work. However, Spallanzani passed away in 1799, and it was the time Bassi had a growing interest in animal and plant biology.
His initial work was on breeding sheep, growing better varieties of potato and to make better wines. In 1807, he started working on diseases of silk-worms. Around 1820 he could prove that it was an external agent that causes silk-worm to be diseased. He was also the first to demonstrate that microorganisms cause infections, and disinfection can get rid of disease. By 1837, he could improve silk production, and prevent infectious diseases in silkworm.
Till 1853, Bassi wrote many papers to suggest that many diseases in human beings (like plague, small pox, cholera, malaria etc) are due to micro-organisms. He gave this hypothesis, three decades before Robert Koch proved this concept, and Louis Pasteur demonstrated germs as cause of diseases.
The dominance of Italian biologists spans over two centuries. Later this work got overshadowed by the Germans and French scientists. Their contribution, however formed the basis for more discoveries in the years to come. It is believed that Louis Pasteur was greatly influenced by their work. Pasteur had the portraits of both Spallanzani and Bassi in his office and also cited their work.