Giulio Cesare la Galla (or Julius Cæsar Lagalla or Giulio Cesare Lagalla) (1576–1624) was a

professor Professor (commonly abbreviated as Prof.) is an Academy, academic rank at university, universities and other post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin as a "person who pr ...

philosophy Philosophy (from , ) is the systematized study of general and fundamental questions, such as those about existence, reason, knowledge, values, mind, and language. Such questions are often posed as problems to be studied or resolved. Some ...

at the Collegio Romano in

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical re ...

. He was born in Padula, at that time part of the

Kingdom of Naples The Kingdom of Naples ( la, Regnum Neapolitanum; it, Regno di Napoli; nap, Regno 'e Napule), also known as the Kingdom of Sicily, was a state that ruled the part of the Italian Peninsula south of the Papal States between 1282 and 1816. It was ...

. Lagalla was educated in philosophy and

medicine Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care pract ...

. He became the official physician of the

papal The pope ( la, papa, from el, πάππας, translit=pappas, 'father'), also known as supreme pontiff ( or ), Roman pontiff () or sovereign pontiff, is the bishop of Rome (or historically the patriarch of Rome), head of the worldwide Cathol ...

galley A galley is a type of ship that is propelled mainly by oars. The galley is characterized by its long, slender hull, shallow draft, and low freeboard (clearance between sea and gunwale). Virtually all types of galleys had sails that could be used ...

s for a period, then came to Rome to lecture in natural philosophy at the Collegio Romano. He apparently became the leading

peripatetic Peripatetic may refer to: *Peripatetic school, a school of philosophy in Ancient Greece *Peripatetic axiom * Peripatetic minority, a mobile population moving among settled populations offering a craft or trade. *Peripatetic Jats There are several ...

of the city, and was counted among the opponents of the Copernican heliocentric theory. Following

Galileo Galileo di Vincenzo Bonaiuti de' Galilei (15 February 1564 – 8 January 1642) was an Italian astronomer, physicist and engineer, sometimes described as a polymath. Commonly referred to as Galileo, his name was pronounced (, ). He was ...

’s observations of the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

by means of a

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe ...

, published in '' Sidereus Nuncius'', Lagalla published a booklet in response. He participated in the demonstrations of the instrument by Galileo and was not among those who doubted the ability of the instrument. But he did debate Galileo's three-dimensional representation of the Moon based on two-dimensional visual observations. In his book ''De Phenomenis in Orbe Lunae'' (published in Venice in 1612) he claimed that the untreated stone (known as "lapis solaris" and shown to him by Galileo Galilei) was unable to give off light only after calcination. We now know that the "Bolognian Stone" was a piece of

barite Baryte, barite or barytes ( or ) is a mineral consisting of barium sulfate ( Ba S O4). Baryte is generally white or colorless, and is the main source of the element barium. The ''baryte group'' consists of baryte, celestine (strontium sulfate), ...

(barium sulphate). The crater Lagalla on the

is named after him.

Bibliography

*''De luce et lumine altera disputatio'' * *''De Immortalitate animorum ex Aristot. sententia'' (1621)

External links

The Discovery of Luminescence: "The Bolognian Stone"
1576 births 1624 deaths 17th-century Italian philosophers {{italy-philosopher-stub