Scientist Priests: Lazzaro Spallanzani

Italy 1729-1799

Lazzaro Spallanzani was born in 1729. “He attended the Jesuit college at Reggio, where he received a sound education in the classics and philosophy.” However, rather than join the Jesuit order, he began to study law. Then his cousin, Laura Bassi, got him interested in science, (1&2) and “at twenty-five he became professor of logic, metaphysics, and Greek in the University of Reggio.” (2) Around the same time, he was also in seminary; he was ordained as a priest in 1757.

“Spallanzani read voraciously but was a persistent skeptic, hesitant to believe anything that he could not prove himself” (3), which turned out to be very important when it came to animalcules, as the scientists who originally carried it out had not been as strenuous in their testing as they should have been. (3) After Spanzalli carried out the tests himself, he published the outcome and criticized the original tests that had been performed. One of the scientists who published the original study sent Spanzalli a message which led to Spanzalli’s research on regeneration, for which he is now known.

In fact, it “was in biology that his work counted for most; his studies in regeneration are still classic.” (2) Among other things, he tested to see if snails could regrow their heads (they could; the brains of snails are not in their heads) (1), how salamanders regrow their tails, and what injuries earthworms could recover from (4). But he didn’t focus solely on regeneration. He also studied the digestive system, tested gravy to see whether Leeuwenhoek was correct to say that microscopic life were truly living organisms, and investigated the mechanics of skipping stones across water (1)

While his theories about digestion and limb regeneration bested those of his contemporaries, Spallanzani did not lord it over them, at least not where they could see, hear, or ever find out about it. (1&4) It is known that his theories likely bested those of his contemporaries because of his “vigorous use of scientific methodologies” (3)

Additionally, Spallanzani’s research into “the development of microscopic life” was a vital link between Antonie von Leeuwenhoek's discovery of animalcules in 1676 and “the research of Louis Pasteur” which took place in 1849, over 170 years later. (1)

Works Referenced