As ill.u.s.trating how, as we know more about the details of medical history, the beginnings of medical science and medical practice are pushed back farther and farther, a discussion in the _Berliner klinische Wochenschrift_ a dozen years ago is of interest. Professor Ernest von Leyden, in sketching the history of the taking of the pulse as an important aid in diagnostics, said that John Floyer was usually referred to as the man who introduced the practice of determining the pulse rate by means of the watch. His work was done about the beginning of the eighteenth century. Professor von Leyden suggested, however, that William Harvey, the English physiologist, to whom is usually attributed the discovery of the circulation of the blood, had emphasized the value of the pulse in medical diagnosis, and also suggested the use of the watch in counting the pulse. Professor Carl Binz, of the University of Bonn, commenting on these remarks of Professor von Leyden, called attention to the fact that more than a century before the birth of either of these men, even the earlier, to whom the careful measurement of the pulse rate is thus attributed as a discovery, a distinguished German churchman, who died shortly after the middle of the fifteenth century, had suggested a method of accurate estimation of the pulse that deserves a place in medical history.
This suggestion is so much in accord with modern demands for greater accuracy in diagnosis that it seems not inappropriate to talk of it as the first definite attempt at laboratory methods in the department of medicine. The maker of the suggestion, curiously enough, was not a practising physician, but a mathematician and scholar, Cardinal Nicholas of Cusa, who is known in history as Cusa.n.u.s from the Latin name of the town Cues on the Moselle River, some twenty-five miles south of Treves, where he was born. His family name, Nicholas Krebs, has been entirely lost sight of in the name derived from his native town, which is the only reason why most of the world knows anything about that town.
Cardinal Cusa.n.u.s suggested that in various forms of disease and at various times of life, as in childhood, boyhood, manhood, and old age, the pulse was very different. It would be extremely valuable to have some method of accurately estimating, measuring, and recording these differences for medical purposes. At that time watches had not yet been invented, and it would have been very difficult to have estimated the time by the clocks, for almost the only clocks in existence were those in the towers of the cathedrals and of the public buildings. The first watches, Nuremberg eggs, as they were called, were not made by Peter Henlein until well on into the next century. The only method of measuring time with any accuracy in private houses was the clepsydra or water-clock, which measured the time intervals by the flow of a definite amount of water. Cardinal Cusa.n.u.s suggested then that the water-clock should be employed for estimating the pulse frequency. His idea was that the amount of water which flowed while a hundred beats of the pulse were counted, should be weighed, and this weight compared with that of the average weight of water which flowed while a hundred beats of the normal pulse of a number of individuals of the same age and const.i.tution were being counted.
This was a very single and a very ingenious suggestion. We have no means of knowing now whether it was adopted to any extent or not. It may seem rather surprising that a cardinal should have been the one to make such a suggestion. Cusa.n.u.s, however, was very much interested in mathematics and in the natural sciences, and we have many wonderful suggestions from his pen. He was the first, for instance, to suggest, more than a century before Copernicus, that the earth was not the centre of the universe, and that it would not be absolutely at rest or, as he said, devoid of all motion. His words are: "_Terra igitur, quae centrum esse nequit, motu omni carere non potest_." He described very clearly how the earth moved round its own axis, and then he added, what cannot fail to be a surprising declaration for those in the modern times who think such an idea of much later origin, that he considered that the earth itself cannot be fixed, but moves as do the other stars in the heavens. The expression is so astonishing at that time in the world"s history that it seems worth the while to give it in its original form, so that it may be seen clearly that it is not any subsequent far-fetched interpretation of his opinion, but the actual words themselves, that convey this idea.
He said: "_Consideravi quod terra ista non potest esse fixa, sed movetur ut aliae stellae._"
How clearly Cusa.n.u.s antic.i.p.ated another phase of our modern views may be judged from what he has to say in "De Docta Ignorantia" with regard to the const.i.tution of the sun. It is all the more surprising that he should by some form of intuition reach such a conclusion, for the ordinary sources of information with regard to the sun would not suggest such an expression except to a genius, whose intuition outran by far the knowledge of his time. The Cardinal said: "To a spectator on the surface of the sun the splendor which appears to us would be invisible, since it contains, as it were, an earth for its central ma.s.s, with a circ.u.mferential envelope of light and heat, and between the two an atmosphere of water and clouds and of ambient air." After reading that bit of precious astronomical science announced nearly five centuries ago, it is easy to understand how Copernicus could have antic.i.p.ated other phases of our knowledge, as he did in his declarations that the figure of the earth is not a sphere, but is somewhat irregular, and that the orbit of the earth is not circular.
Cusa.n.u.s was an extremely practical man, and was constantly looking for and devising methods of applying practical principles of science to ordinary life. As we shall see in discussing his suggestion for the estimation of the pulse rate later on, he made many other similar suggestions for diagnostic purposes in medicine, and set forth other applications of mathematics and mechanics to his generation.
Many of Cusa.n.u.s" books have curiously modern names. He wrote, for instance, a series of mathematical treatises, in Latin of course, on "Geometric Trans.m.u.tations," on "Arithmetical Complements," on "Mathematical Complements," on "Mathematical Perfection," and on "The Correction of the Calendar." In his time the calendar was in error by more than nine days, and Cusa.n.u.s was one of those who aroused sufficient interest in the subject, so that in the next century the correction was actually made by the great Jesuit mathematician, Father Clavius. Perhaps the work of Cusa.n.u.s that is best known is that "On Learned Ignorance--De Docta Ignorantia," in which the Cardinal points out how many things that educated people think they know are entirely wrong. It reminds one very much of Josh Billings"s remark that it is not so much the ignorance of mankind that makes them ridiculous, as the knowing so many things that ain"t so. It is from this work that the astronomical quotations which we have made are taken. The book that is of special interest to physicians is his dialogue "On Static Experiments," which he wrote in 1450, and which contains the following pa.s.sages:
"Since the weight of the blood and the urine of a healthy and of a diseased man, of a young man and an old man, of a German and an African, is different for each individual, why would it not be a great benefit to the physician to have all of these various differences cla.s.sified? For I think that a physician would make a truer judgment from the weight of the urine viewed in connection with its color than he could make from its color alone, which might be fallacious. So, also, weight might be used as a means of identifying the roots, the stems, the leaves, the fruits, the seeds, and the juice of plants if the various weights of all the plants were properly noted, together with their variety, according to locality. In this way the physician would appreciate their nature better by means of their weight than if he judged them by their taste alone. He might know, then, from a comparison of the weights of the plants and their various parts when compared with the weight of the blood and the urine, how to make an application and a dosage of drugs from the concordances and differences of the medicaments, and even might be able to make an excellent prognosis in the same way. Thus, from static experiments, he would approach by a more precise knowledge to every kind of information.
"Do you not think if you would permit the water from the narrow opening of a clepsydra [water-clock] to flow into a basin for as long as was necessary to count the pulse a hundred times in a healthy young man, and then do the same thing for an ailing young man, that there would be a noticeable difference between the weights of the water that would flow during the period? From the weight of the water, therefore, one would arrive at a better knowledge of the differences in the pulse of the young and the old, the healthy and the unhealthy, and so, also, as to information with regard to various diseases, since there would be one weight and, therefore, one pulse in one disease, and another weight and another pulse in another disease. In this way a better judgment of the differences in the pulse could be obtained than from the touch of the vein, just as more can be known from the urine about its weight than from its color alone.
"Just in the same way would it not be possible to make a more accurate judgment with regard to the breathing, if the inspirations and expirations were studied according to the weight of the water that pa.s.sed during a certain interval? If, while water was flowing from a clepsydra, one were to count a hundred expirations in a boy, and then in an old man, of course, there would not be the same amount of water at the end of the enumeration. Then this same thing might be done for other ages and states of the body. As a consequence, when the physician once knew what the weight of water that represented the number of expirations of a healthy boy or youth, and then of an individual of the same age ill of some infirmity or other, there is no doubt that, by this observation, he will come to a knowledge of the health or illness and something about the case, and, perhaps, also with more certainty would be able to choose the remedy and the dose required. If he found in a healthy young man apparently the same weight as in an old and decrepit individual, he might readily be brought to the conclusion that the young man would surely die, and in this way have some evidence for his prognosis in the case.
Besides, if in fevers, in the same way, careful studies were made of the differences in the weight of water for pulse and respiration in the warm and the cold paroxysms, would it not be possible thus to know the disease better and, perhaps, also get a more efficacious remedy?"
As will be seen from this pa.s.sage, Cusa.n.u.s had many more ideas than merely the accurate estimation of the pulse frequency when he suggested the use of the water-clock. Evidently the thought had come to him that the specific gravity of the substances, that is, their weight in comparison to the weight of water, might be valuable information.
Before his time, physicians had depended only on the color and the taste of the urine for diagnostic purposes. He proposed that they should weigh it, and even suggested that they should weigh, also, the blood, I suppose in case of venesection, for comparison"s sake. He also thought that the comparative weight of various roots, stems, leaves, juices of plants might give hints for the therapeutic uses of these substances.
This is the sort of idea that we are apt to think of as typically modern. Specific gravities and atomic weights have been more than once supposed to represent laws in therapeutics, which so far, however, we have not succeeded in finding, but it is interesting to realize that it is nearly five hundred years since the first thought in this line was clearly expressed by a distinguished thinker and scientific writer.
There are many interesting expressions in Cusa.n.u.s" writings which contradict most of the impressions commonly entertained with regard to the scholars of the Middle Ages. It is usually a.s.sumed that they did not think seriously, but speculatively, that they feared to think for themselves, neglected the study of nature around them, considered authority the important source of knowledge, and were as far as possible from the standpoint of modern scientific students and investigators.
Here is a pa.s.sage from Nicholas, on knowing and thinking, that might well have been written by a great intellectual man at any time in the world"s history, and that could only emanate from a profound scholar at any time.
"To know and to think, to see the truth with the eye of the mind, is always a joy. The older a man grows the greater is the pleasure which it affords him, and the more he devotes himself to the search after truth, the stronger grows his desire of possessing it. As love is the life of the heart, so is the endeavor after knowledge and truth the life of the mind. In the midst of the movements of time, of the daily work of life, of its perplexities and contradictions, we should lift our gaze fearlessly to the clear vault of heaven, and seek ever to obtain a firmer grasp of and a keener insight into the origin of all goodness and beauty, the capacities of our own hearts and minds, the intellectual fruits of mankind throughout the centuries, and the wondrous works of nature around us; at the same time remembering always that in humility alone lies true greatness, and that knowledge and wisdom are alone profitable in so far as our lives are governed by them."
The career of Nicholas of Cusa is interesting, because it sums up so many movements, and, above all, educational currents in the fifteenth century. He was born in the first year of the century, and lived to be sixty-four. He was the son of a wine grower, and attracted the attention of his teachers because of his intellectual qualities. In spite of comparatively straitened circ.u.mstances, then, he was afforded the best opportunities of the time for education. He went first to the school of the Brethren of the Common Life at Deventer, the intellectual cradle of so many of the scholars of this century. Such men as Erasmus, Conrad Mutia.n.u.s, Johann Sintheim, Hermann von dem Busche, whom Strauss calls "the missionary of human wisdom," and the teacher of most of these, Alexander Hegius, who has been termed the schoolmaster of Germany, with Nicholas of Cusa and Rudolph Agricola and others, who might readily be mentioned, are the fruits of the teaching of these schools of the Brethren of the Common Life, in one of which Thomas a Kempis, the author of "The Imitation of Christ," was, for seventy years out of his long life of ninety, a teacher.
Cusa.n.u.s succeeded so well at school that he was later sent to the University of Heidelberg, and subsequently to Padua, where he took up the study of Roman law, receiving his doctorate at the age of twenty-three. This series of educational opportunities will be surprising only to those who do not know educational realities at the beginning of the fifteenth century. There has never been a time when a serious seeker after knowledge could find more inspiration. On his return to Germany, Father Krebs became canon of the cathedral in Coblenz. This gave him a modest income, and leisure for intellectual work which was eagerly employed. He was scarcely more than thirty when he was chosen as a delegate to the Council at Basel. After this he was made Archdeacon of the Cathedral of Luttich, and from this time his rise in ecclesiastical preferment was rapid. He had attracted so much attention at the Council of Basel that he was chosen as a legate of the Pope for the bringing about certain reforms in Germany. Subsequently he was sent on ecclesiastical missions to the Netherlands, and even to Constantinople. At the early age of forty he was made a Cardinal. After this he was always considered as one of the most important consultors of the Papacy in all matters relating to Germany. During the last twenty-five years of his life in all the relations of the Holy See to Germany, appeal was constantly made to the wisdom, the experience, and the thoroughly conservative, yet foreseeing, judgment of this son of the people, whose education had lifted him up to be one of the leaders of men in Europe.
It was during this time that he wrote most of his books on mathematics, which have earned for him a prominent place in Cantor"s "History of Mathematics," about a score of pages being devoted to his work. Much of his thinking was done while riding on horseback or in the rude vehicles of the day on the missions to which he was sent as Papal Legate. He is said to have worked out the formula for the cycloid curve while watching the path described by flies that had lighted on the wheels of his carriage, and were carried forward and around by them. His scientific books, though they included such startling antic.i.p.ations of Copernicus"
doctrines as we have already quoted (Copernicus did not publish the first sketch of his theory for more than a quarter of a century after Cusa.n.u.s" death), far from disturbing his ecclesiastical advancement or injuring his career as a churchman, seem actually to have been considered as additional reasons for considering him worthy of confidence and consultation.
As the result of his careful studies of conditions in Germany, he realized very clearly how much of unfortunate influence the political status of the German people, with their many petty rulers and the hampering of development consequent upon the trivial rivalries, the constant bickerings, and the inordinate jealousies of these numerous princelings, had upon his native country. Accordingly, towards the end of his life he sketched what he thought would be the ideal political status for the German people. As in everything that he wrote, he went straight to the heart of the matter and, without mincing words, stated just exactly what he thought ought to be done. Considering that this scheme of Cusa.n.u.s for the prosperity and right government of the German people was not accomplished until more than four centuries after his death, it is interesting, indeed, to realize how this clergyman of the middle of the fifteenth century should have come to any such thought.
Nothing, however, makes it clearer than this, that it is not time that fosters thinking, but that great men at any time come to great thoughts.
Cusa.n.u.s wrote:
"The law and the kingdom should be placed under the protection of a single ruler or authority. The small separate governments of princes and counts consume a disproportionately large amount of revenue without furnishing any real security. For this reason we must have a single government, and for its support we must have a definite amount of the income from taxes and revenues yearly set aside by a representative parliament and before this parliament (reichstag) must be given every year a definite account of the money that was spent during the preceding year."
Cusa.n.u.s" life and work stand, then, as a type of the accomplishment, the opportunities, the power of thought, the practical scholarship, the mathematical accuracy, the fine scientific foresight of a scholar of the fifteenth century. For us, in medicine, it is interesting indeed to realize that it is from a man of this kind that a great new departure in medicine with regard to the employment of exact methods of diagnosis had its first suggestion in modern times. The origin of that suggestion is typical. It has practically always been true that it was not the man who had exhausted, or thought that he had done so, all previous medical knowledge, who made advances in medicine for us. It has nearly always been a young man early in his career, and at a time when, as yet, his mind was not overloaded with the medical theories of his own time.
Cusa.n.u.s was probably not more than thirty when he made the suggestion which represents the first practical hint for the use of laboratory methods in modern medicine. It came out of his thoughtful consideration of medical problems rather than from a store of garnered information as to what others thought. It is a lesson in the precious value of breadth of education and serious training of mind for real progress at all times.
XIV
BASIL VALENTINE, LAST OF THE ALCHEMISTS, FIRST OF THE CHEMISTS
"Fieri enim potest ut operator erret et a via regia deflectat, sed ut erret natura quando recte tractatur fieri non potest."
"For it is quite possible that the physician should err and be turned aside from the straight (royal) road, but that nature when she is rightly treated should err is quite impossible."
This is one of the preliminary maxims of a treatise on medicine written by a physician born not later than the first half of the fifteenth century, and who may have lived even somewhat earlier. We are so p.r.o.ne to think of the men of that time as utterly dependent on authority, not daring to follow their own observation, suspecting nature, and almost sure to be convinced that only by going counter to her could success in the treatment of disease be obtained, that it is a surprise to most people to find how completely the att.i.tude of mind, that is supposed to be so typically modern in this regard, was antic.i.p.ated full four centuries ago. There are other expressions of this same great physician and medical writer, Basil Valentine, which serve to show how faithfully he strove with the lights that he had to work out the treatment of patients, just as we do now, by trying to find out nature"s way, so as to imitate her beneficent processes and purposes. It is quite clear that he is but one of many faithful, patient observers and experimenters--true scientists in the best sense of the word--who lived in all the centuries of the Middle Ages.
Speculations and experiments with regard to the elixir of life, the philosopher"s stone, and the trans.m.u.tation of metals, are presumed to have filled up all the serious interests of the alchemists, supposed to be almost the only scientists of those days. As a matter of fact, however, men were making original observations of profound significance, and these were considered so valuable by their contemporaries that, though printing had not yet been invented, even the immense labor involved in the manifold copying of large folio volumes by the slow hand process did not suffice to deter them from multiplying the writings of these men so numerously that they were preserved in many copies for future generations, until the printing press came to perpetuate them.
Of this there is abundant evidence in the preceding pages as regards medicine, and, above all, surgery, while a summary of accomplishments of workers in other departments will be found in Appendix II, "Science at the Medieval Universities."
At the beginning of the twentieth century, with some of the supposed foundations of modern chemistry crumbling to pieces under the influence of the peculiarly active light thrown upon our nineteenth century chemical theories by the discovery of radium, and our observations on radio-active elements generally, there is a reawakening of interest in some of the old-time chemical observers, whose work used to be laughed at as so unscientific, or, at most, but a caricature of real science, and whose theory of the trans.m.u.tation of elements into one another was considered so absurd. It is interesting in the light of this to recall that the idea that the elementary substances were essentially distinct from each other, and that it would be impossible under any circ.u.mstances to convert one element into another, belongs entirely to the nineteenth century. Even so deeply scientific a mind as that of Newton, in the preceding century, could not bring itself to acknowledge the tradition, that came to be accepted subsequent to his time, of the absurdity of metallic transformation. On the contrary, he believed quite formally in trans.m.u.tation as a basic chemical principle, and declared that it might be expected to occur at any time. He had seen specimens of gold ores in connection with metallic copper, and concluded that this was a manifestation of the natural transformation of one of these yellow metals into the other.
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 trans.m.u.tation process constantly at work, the ideas of the older chemists cease entirely to be a subject for amus.e.m.e.nt. 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 trans.m.u.te 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 ma.n.u.scripts 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 t.i.tle 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 const.i.tuents 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 p.r.o.ne 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 Allb.u.t.t, 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 trans.m.u.tation of metals.
Albertus Magnus" other great scientific pupil, Roger Bacon, the English Franciscan friar, followed more closely in the scientific ways of his great master, devoting himself almost entirely to the physical sciences. Altogether he wrote some eighteen treatises on chemical subjects. For a long time it was considered that he was the inventor of gunpowder, though this is now known to have been introduced into Europe by the Arabs. Roger Bacon studied gunpowder and various other explosive combinations in considerable detail, and it is for this reason that he obtained the undeserved reputation of being an original discoverer in this line. How well he realized how much might be accomplished by means of the energy stored up in explosives, can, perhaps, be best appreciated from the fact that he suggested that boats would go along the rivers and across seas without either sails or oars, and that carriages would go along the streets without horse or man power. He considered that man would eventually invent a method of harnessing these explosive mixtures, and of utilizing their energies for his purposes without danger. It is curiously interesting to find, as we begin the twentieth century, and gasolene is so commonly used for the driving of automobiles and motor boats, and is being introduced even into heavier transportation as the most available source of energy for suburban traffic, at least, that this generation should only be fulfilling the idea of the old Franciscan friar of the thirteenth century, who prophesied that in explosives there was the secret of eventually manageable energy for transportation purposes.
Succeeding centuries were not as fruitful in great scientists as the thirteenth, and yet, in the second half of the thirteenth, there was a Pope, John XXI, who had been a physician and professor of medicine before his election to the Papacy, three of whose scientific treatises--one on the trans.m.u.tation of metals, which he considers an impossibility, at least as far as the manufacture of gold and silver was concerned; a treatise on diseases of the eyes, to which good authorities have not hesitated to give lavish praise for its practical value, considering the conditions in which it was written; and, finally, his treatise on the preservation of the health, written when he was himself over eighty years of age--are all considered by good authorities as worthy of the best scientific spirit of the time.
During the fourteenth century, Arnold of Villanova, the inventor of nitric acid, and the two Hollanduses, kept up the tradition of original investigation in chemistry. Altogether there are some dozen treatises from these three men on chemical subjects. The Hollanduses particularly did their work in a spirit of thoroughly frank, original investigation.
They were more interested in minerals than in any other cla.s.s of substances, but did not waste much time on the question of trans.m.u.tation of metals. Professor Thompson, the professor of chemistry at Edinburgh, said, in his "History of Chemistry," many years ago, that the Hollanduses give very clear descriptions of their processes of treating minerals in investigating their composition, and these serve to show that their knowledge was by no means entirely theoretical, or acquired only from books.
It is not surprising, then, to have a great investigating pharmacologist come along sometime about the beginning of the fifteenth century, when, according to the best authorities, Basil Valentine was born. From traditions he seems to have had a rather long life, and his years run nearly parallel with his century. His career is a typical example of the personally obscure and intellectually brilliant lives which the old monks lived. Probably in nothing have recent generations been more deceived in historical matters than in their estimation of the intellectual attainments and accomplishment of the old monks. The more that we know of them, not from second-hand authorities, but from their own books and from what they accomplished in art and architecture, in agriculture, in science of all kinds, the more do we realize what busy men they were, and appreciate what genius they often brought to the solution of great problems. We have had much negative pseudo-information brought together with the definite purpose of discrediting monasticism, and now that positive information is gradually being acc.u.mulated, it is almost a shock to find how different are the realities of the story of the intellectual life during the Middle Ages from what many writers had pictured them.
To those who may be surprised that a man who did great things in medicine should have lived during the fifteenth century, it may be well to recall the names and a little of the accomplishment of the men of this period, who were Basil Valentine"s contemporaries, at least in the sense that some portion of their lives and influence was coeval with his. Before the end of this century Columbus had discovered America, and by no happy accident, for many men of his generation did correspondingly great work. Cardinal Nicholas of Cusa had developed mathematics and applied mathematical ideas to the heavens, so that he could announce the conclusion that the earth was a star, like the other stars, and moved in the heavens as they do. Contemporary with Cusa.n.u.s was Regiomonta.n.u.s, who has been proclaimed the father of modern astronomy, and a distinguished mathematician. Toscanelli, the Florentine astronomer, whose years run almost parallel with those of the fifteenth century, did fine scholarly work, which deeply influenced Columbus and the great navigators of the time. The universities in Italy were attracting students from all over Europe, and such men as Linacre and Dr. Caius went down there from England. Raphael was but a young man at the end of the century, but he had done some noteworthy painting before it closed. Leonardo da Vinci was born just about the middle of the century, and did some marvellous work before the end of that century.
Michael Angelo was only twenty-five at the close of the century, but he, too, did fine work, even at this early age. Among the other great Italian painters of this century are Fra Angelico, Perugino, Raphael"s master, Pinturicchio, Signorelli, the pupil of his uncle, Vasari, almost as distinguished, Botticelli, t.i.tian, and very many others, who would have been famous leaders in art in any other but this supremely great period.