In the meantime Father Kircher was issuing notable books on his always favorite subject of the Oriental languages. In 1650 there appeared "Obeliscus Pamphilius," containing an explanation of the hieroglyphics to be found on the obelisk which by the order of Innocent X, a member of the Pamfili family, was placed in the Piazza Navona by Bernini. This is no mere pamphlet, as might be thought, but a book of 560 pages. In 1652 there appeared "OEdipus AEgyptiacus," that is, the revealer of the sphinx-like riddle of the Egyptian ancient languages. In 1653 a second volume of this appeared, and in 1655 a third {124} volume. It was considered so important that it was translated into Russian and other Slav languages, besides several other European languages. His book, "Lingua AEgyptiaca Restituta," which appeared in 1644, when Kircher was forty-two years of age, is considered to be of value yet in the study of Oriental languages, and was dedicated to the patron, Emperor Ferdinand III, whose liberality made its publication possible. It is often a subject for conjecture just how science was studied and taught in centuries before the nineteenth, and just what text-books were employed. A little familiarity with Father Kircher's publications, however, will show that there was plenty of very suitable material for text-books to be found in his works. Under his own direction, what at the present time would be called a text-book of physics, but which at that time was called "Physiologia Experimentalis," was issued, containing all the experimental and demonstrative parts of his various books on chemistry, physics, music, magnetism, and mechanics, as well as acoustics and optics. This formed the groundwork of most text-books of science for a full century afterwards. Indeed, until the beginning of the distinctly modern science of chemistry with the discoveries of Priestley and Lavoisier, there was to be little added of serious import in science. Perhaps the most commendable feature of Father Kircher's books is the fact that he himself seems never to have considered that he had {125} exhausted a subject. The first work he published was on magnetism. Some twelve years later he returned to the subject, and wrote a more extensive work, containing many improvements over the first volume. The same thing is true of his studies in sound. In 1650, when not quite fifty years of age, he issued his "Musurgia Universalis," a sub-title of which stated that it contains the whole doctrine of sound and the practical and theoretical philosophy of music. A little over twenty years later, however, he published the "Phonurgia Nova," the sub-title of which showed that it was mainly concerned with the experimental demonstration of various truths in acoustics and with the development of the doctrine he had originally stated in the "Musurgia."