With the discovery that radium transforms itself into helium, and that, indeed, all the so-called radioactivities of the heavy metals are probably due to a natural transmutation process constantly at work, the ideas of the older chemists cease entirely to be a subject for amusement. The physical chemists of the present day are very ready to admit that the old teaching of the absolute independence of something over seventy elements is no longer tenable, except as a working hypothesis. The doctrine of "matter and form," taught for so many centuries by the scholastic philosophers, which proclaimed that all matter is composed of two principles, an underlying material substratum, and a dynamic or informing principle, has now more acknowledged verisimilitude, or lies at least closer to the generally accepted ideas of the most progressive scientists, than it has at any time for the last two or three centuries. Not only the great physicists, but also the great chemists, are speculating along lines that suggest the existence of but one form of matter, modified according to the energies that it possesses under a varying physical and chemical environment. This is, after all, only a restatement in modern times of the teaching of St. Thomas of Aquin, in the thirteenth century.

It is not surprising, then, that there should be a reawakening of interest in the lives of some of the men, who, dominated by some of the earlier scholastic ideas, by the tradition of the possibility of finding the philosopher's stone, which would transmute the baser metals into the precious metals, devoted themselves with quite as much zeal as any modern chemist to the observation of chemical phenomena. One of the most interesting of these—indeed, he might well be said to be the greatest of the alchemists—is the man whose only name that we know is that which appears on a series of manuscripts written in the High German dialect of the end of the fifteenth and the beginning of the sixteenth century. That name is Basil Valentine, and the writer, according to the best historical traditions, was a Benedictine monk. The name Basil Valentine may only have been a pseudonym, for it has been impossible to trace it among the records of the monasteries of the time. That the writer was a monk, however, there seems to be no room for doubt, for his writings give abundant evidence of it, and, besides, in printed form they began to have their vogue at a time when there was little likelihood of their being attributed to a monastic source, unless an indubitable tradition connected them with some monastery.

This Basil Valentine (to accept the only name we have) did so much for the science of the composition of substances that he eminently deserves the designation that has been given him of the last of the alchemists and the first of the chemists. There is practically a universal recognition of the fact now that he deserves also the title of the Founder of Pharmaceutical Chemistry, not only because of the value of the observations contained in his writings, but also because of the fact that they proved so suggestive to certain scientific geniuses during the century succeeding Valentine's life. Almost more than to have added to the precious heritage of knowledge for mankind, it is a boon for a scientific observer to have awakened the spirit of observation in others, and to be the founder of a new school of thought. This Basil Valentine undoubtedly did, and, in the Renaissance, the incentive from his writings for such men as Paracelsus is easy to appreciate.

Besides, his work furnishes evidence that the investigating spirit was abroad just when it is usually supposed not to have been, for the Thuringian monk surely did not do all his investigation alone, but must have owed, as well as given, many a suggestion to his contemporaries.

Some ten years ago, when Sir Michael Foster, professor of physiology in the University of Cambridge, England, was invited to deliver the Lane Lectures at the Cooper Medical College in San Francisco, he took for his subject "The History of Physiology." In the course of his lecture on "The Rise of Chemical Physiology" he began with the name of Basil Valentine, who first attracted men's attention to the many chemical substances around them that might be used in the treatment of disease, and said of him:

"He was one of the alchemists, but in addition to his inquiries into the properties of metals and his search for the philosopher's stone, he busied himself with the nature of drugs, vegetable and mineral, and with their action as remedies for disease. He was no anatomist, no physiologist, but rather what nowadays we should call a pharmacologist. He did not care for the problem of the body, all he sought to understand was how the constituents of the soil and of plants might be treated so as to be available for healing the sick and how they produced their effects. We apparently owe to him the introduction of many chemical substances, for instance of hydrochloric acid, which he prepared from oil and vitriol of salt, and of many vegetable drugs. And he was apparently the author of certain conceptions which, as we shall see, played an important part in the development of chemistry and of physiology. To him, it seems, we owe the idea of the three 'elements,' as they were and have been called, replacing the old idea of the ancients of the four elements—earth, air, fire, and water. It must be remembered, however, that both in the ancient and the new idea the word 'element' was not intended to mean that which it means to us now, a fundamental unit of matter, but a general quality or property of matter. The three elements of Valentine were: (1) sulphur, or that which is combustible, which is changed or destroyed, or which at all events disappears during burning or combustion; (2) mercury, that which temporarily disappears during burning or combustion, which is dissociated in the burning from the body burnt, but which may be recovered, that is to say, that which is volatile, and (3) salt, that which is fixed, the residue or ash which remains after burning."

It is a little bit hard in our time for most people to understand just how such a development of thoroughly scientific chemical notions, with investigations for their practical application, should have come before the end of the Middle Ages. This difficulty of understanding, however, we are coming to realize in recent years, is entirely due to our ignorance of the period. We have known little or nothing about the science of the Middle Ages, because it was hidden away in rare old books, in rather difficult Latin, not easy to get at, and still less easy to understand always, and we have been prone to conclude that since we knew nothing about it, there must have been nothing. Just inasmuch as we have learned something definite about the medieval scholars, our admiration has increased. Professor Clifford Allbutt, the Regius Professor of Medicine at the University of Cambridge, in his Harveian Oration, delivered before the Royal College of Physicians in 1900, on "Science and Medieval Thought" (London, 1901), declared that "the schoolmen, in digging for treasure, cultivated the field of knowledge even for Galileo and Harvey, for Newton and Darwin." He might have added that they had laid foundations in all our modern sciences, in chemistry quite as well as in astronomy, physiology, and the medical sciences, in mathematics and botany.

In chemistry the advances made during the thirteenth, fourteenth, and fifteenth centuries were, perhaps, even more noteworthy than those in any other department of science. Albertus Magnus, who taught at Paris, wrote no less than sixteen treatises on chemical subjects, and, notwithstanding the fact that he was a theologian as well as a scientist, and that his printed works fill some fifteen folio volumes, he somehow found the time to make many observations for himself, and performed numberless experiments in order to clear up doubts. The larger histories of chemistry accord him his proper place, and hail him as a great founder in chemistry, and a pioneer in original investigation.

Even St. Thomas of Aquin, much as he was occupied with theology and philosophy, found some time to devote to chemical questions. After all, this is only what might have been expected of the favorite pupil of Albertus Magnus. Three treatises on chemical subjects from Aquinas' pen have been preserved for us, and it is to him that we are said to owe the use, in the Western world at least, of the word amalgam, which he first employed in describing various chemical methods of metallic combination with mercury that were discovered in the search for the genuine transmutation of metals.