ARNAUD, or ARNOLDUS, DE VILLA NOVA, a famous physician and alchemist, who lived about the end of the thirteenth and beginning of the fourteenth century. He studied at Paris and Montpellier, and improved himself by visiting the schools of Italy and Spain. He was well acquainted with languages, particularly with the Greek, Hebrew, and Arabic. His desire after the acquisition of knowledge was ardent, but it carried him too far in his researches. He put unlimited faith in astrology, and published a prediction that the consummation of the world would take place in the year 1335. He practised physic at Paris for some time; but having advanced some new doctrines, he drew upon himself the resentment of the university; and his friends, fearing he might be arrested, persuaded him to retire from that city. He went to Sicily, where he was received by king Frederic of Aragon with the greatest marks of kindness and esteem. Some time afterwards this prince sent him to France to attend Pope Clement in an illness; and in this voyage he perished by shipwreck on the coast of Genoa about the year 1313.
Arnaud has been called the discoverer of the sulphuric, the muriatic, and the nitric acids, as well as of the essential oil of turpentine; and is said to have been the first to give regular scientific details of the process of distillation; but Dr. Hoefler (Histoire de la Chimie, tom. i., p. 385) has shown that all these discoveries were made long before the time of Arnaud. His works, with a life prefixed, were first printed at Lyons in 1504, in one volume folio, and again in 1520 with the notes of Nicholas Tolerus; and at Basil in 1515 and 1585.