Nicholas Callan and experimental philosophy under Dr. Cornelius Denvir. He introduced the experimental method into his teaching, and had an interest in electricity and magnetism. Callan was ordained a priest in 1823 and went to Rome to study at Sapienza University, obtaining a doctorate in divinity in 1826. While in Rome he became acquainted with the work of the pioneers in electricity such as Luigi Galvani (1737–1798) who was a pioneer in modern obstetrics and Alessandro Volta (1745–1827) who is known especially for the development of the electric battery. In 1826, Callan returned to Maynooth as the new Professor of Natural Philosophy
Will-o'-the-wisp create ephemeral fires. Furthermore, phosphine produces phosphorus pentoxide as a by-product, which forms phosphoric acid upon contact with water vapor, which can explain "viscous moisture" sometimes described as accompanying ignis fatuus. In 1776, Alessandro Volta first proposed that natural electrical phenomena (like lightning) interacting with methane marsh gas may be the cause of ignis fatuus. This was supported by the British polymath Joseph Priestley in his series of works "Experiments and Observations on Different Kinds of Air" (1772–1790); and by the French physicist Pierre Bertholon de Saint-Lazare in "De l’électricité des météores" (1787). Early critics of the marsh gas hypothesis