The thirteenth century saw the rise of a number of great physical scientists, who made observations that anticipated much more of our modern views on scientific problems than is usually thought. One of the greatest of the chemists of the thirteenth century was Albert the Great, or Albertus Magnus, as he is more familiarly called, who taught for many years at the University of Paris. He was a theologian as well as a physician and a scientist. His works have been published in twenty-one folio volumes, which will give some idea of the immense industry of the man. Those relating to chemistry are as follows: Concerning Metals and Minerals; Concerning Alchemy; A Treatise on the Secrets of Chemistry; A Brief Compend on the Origin of the Metals; A Concordance, that is, a Collection, of Observations from Many Sources, with Regard to the Philosopher's {135} Stone; A Treatise on Compounds; a book of eight chapters on the Philosopher's Stone. Most of these are to be found in his works under the general heading "Theatrum Chemicum." Thomson, in his "History of Chemistry," says, that they are, in general, plain and intelligible. Albertus Magnus's most famous pupil was the celebrated Thomas Aquinas. Three of his works are on chemistry: The Intimate Secrets of Alchemy; on the Essence and Substance of Minerals; and finally, later in life, the Wonders of Alchemy. It is in this last work, it is said, that the word _amalgam_ occurs for the first time. While Thomas Aquinas and Albertus Magnus were working in France and Germany, Roger Bacon was doing work of similar nature at Oxford in England. Altogether, he has eighteen treatises on chemical problems. Some of these contain wonderful anticipations of modern chemistry. After Roger Bacon came Raymond Lully, who wrote, in all, sixteen treatises on chemical subjects. At about the same time, Arnold of Villanova was teaching medicine at Paris and paying special attention to chemistry. From him there are twenty-one treatises on chemical subjects still extant. Arnold of Villanova died on the way to visit Pope Clement V., the immediate predecessor of John, who lay sick unto death at Avignon. It is evident, then, that there was no spirit of opposition to chemistry gradually forming itself in ecclesiastical circles, and about to be expressed in a decree by John. The chemists of the thirteenth century had been among the most distinguished churchmen of the period. One of them at least, Thomas Aquinas, had been declared a saint. Another, Albertus Magnus, has been given the title of Blessed, signifying that his life and {136} works are worthy of all veneration. Pope John XXII. had as a young man been a student of these men at the University of Paris, and would surely have imbibed the tradition of their interest in the physical sciences. That he should have unlearned all their lessons seems out of the question.