The following selections will give an idea of the natural science of
the Middle Ages. In introducing them, the Editor
will attempt to give some connected account of them to show that though
their study seems to involve a few difficulties, their explanation is simple,
and will not make too great a demand on the reader’s patience.
From the earliest times men have asked themselves two questions about nature: 'Why?' and 'How?' Medieval science concerned itself with the former ; modern science thinks it has learnt that no answer to that question can be given it, and concerns itself with the latter. It thus happens that the more one becomes in sympathy with the thought of our time, the less one can interest one's self in the work of the past, distinguished as it is by its disregard of all we think important, and by its striving for an unattainable goal.
It is, however, necessary, if we would enjoy Chaucer, Dante, and Shakespeare, to obtain some notion of that system of the universe from which they drew so many of their analogies. The symbolism of Dante appears to us unnaturally strained until we know that the science of his day saw everything as symbolic. And how could we appreciate the strength of Chaucer's metaphor:
Our first extracts explain themselves. They deal' with the mystery of the constitution' of substances, as fascinating to us as to the early Greeks, and begin with definitions of matter and form.
The principal design of early philosophers in physics was to explain how everything was generated, and to trace the different states through which things pass until they become perfect. They observed that as a thing is not generated out of any other indifferently, for example, that marble is not capable of making flesh, all bodies cannot be compounded of principles alone, connected in a simple way, but imagined they could be made up of a few simple compounds. These ultimate compounds, if we may so express it, were their elements. The number of elements was variously estimated, but was generally taken as four, a number arrived at rather from the consideration of the sensations bodies awaken in us, than from the study of bodies themselves. Aristotle gives us the train of thought by which the number is reached. He considers the qualities observed by the senses, classifying them as Heat, Cold, Dryness or Hardness, and Moistness or Capability of becoming liquid These may partially co-exist, two at a time, in the same substance. There are thus four possible combinations, Cold and dry, Cold and moist, Hot and dry, Hot and moist. He then names these from their prototypes Earth, Water, Fire, and Air, distinguishing these elements from the actual Earth, etc., of every-day life.
The habit of extending analogies beyond their legitimate application was a source of confusion in the early ages of science. Most of the superstitions of primitive religion, of astrology, and of alchemy, arose from this source. A good example is the extensions of the metaphor in the words generation and Corruption: words in constant use in scientific works until the nineteenth century began. Generation is the production of a substance that before was not, and corruption is the destruction of a substance, by its ceasing to be what it was before. Thus, fire is generated, and wood is corrupted, when the latter is burnt. But the implicit metaphor in the use of the terms likens substances to the human body, their production and destruction implies liability to disease, and thus prepares the way for the notion of the elixir, which is first a potion giving long life, and curing bodily ailments, and only after some time a remedy for diseased metals-the philosophers stone.
It will be seen that the theory of the medieval alchemist was that matter is an entity filling all space, on which in different places different forms were impressed. The elements were a preliminary grouping of these, and might be present, two, three, or four at a time, in any substance. No attempt was ever made to separate these elements by scientific men, just as no attempt is ever made to isolate the ether of the physical speculation of to-day. The theory of modern physicists with its ether and vortices, answers almost exactly to the matter and form of the ancients, the nature of the vortices conditioning matter.
The extracts from Book XI. bring us to another class of substances. All compound bodies are classified as imperfect or perfect. Imperfect compounds, or meteors, to some extent resemble elements. They are fiery, as the rainbow, or watery, as dew. Our extract on the rainbow is somewhat typical of the faults of ancient science. A note is taken of a rare occurrence-a lunar rainbow--but in describing the common one, an error of the most palpable kind is made. The placing of blue as the middle and green as the lowest colour is obviously wrong, and is inexplicable if we did not know how facts were cut square with theories in old days.
In the next extract Bartholomew's account of the spirits animating man is quoted at length. It gives us the medieval theory as to the means by which life, motion, and knowledge were shown in the body. Every reader of Shakespeare or Chaucer becomes familiar with the vital, animal and natural spirits. They were supposed to communicate with all parts of the body by means of the arteries or worsen, 'the nimble spirits in their arteries,' and the sinews or nerves. The word sinew, by the way, is exactly equal to our word nerve, and ayenward, as our author would say. Hamlet, when he bursts from his friends, explains his vigour by the rush of the spirit into the arteries, which makes
The natural spirit is generated in the liver, the seat of digestion, 'there where our nourishment is administered', it then passes to the heart, and manifests itself as the spirit of life; from thence it passes to the brain, where it is the animal spirit--’spirit animate' Rossetti calls it-dwelling in the brain.
In the brain there are three ventricles or chambers, the foremost being the 'cell fantastike' of the Knight's Tale, the second the logistic, and the third the chamber of memory, where 'memory the warder of the brain,' keeps watch over the passage of the spirit into the 'sinews' of moving. Into the foremost cell come all the perceptions of sight, hearing, etc., and thus we have the opportunity for
As a specimen of the physical science of the time the Editor gives extracts from the chapter on light.
The introduction of extracts enough to give some idea of the medieval astronomy would have made such large demands on the patience of the reader that the Editor has decided with some regret to omit them altogether. The universe is considered to be a sphere, whose centre is the earth and whose circumference revolved about two fixed points. Our author does not decide the nice point in dispute between the philosophers and the theologians, the former holding that there is only one, the latter insisting on seven heavens-the fairy, ethereal, olympian, fiery, firmament, watery, and empyrean.
The firmament, that
Having considered the simpler substances, those composed of pure elemental forms, and those resembling them-the meteors- we turn to the perfect compounds, those which have assumed substantial forms, as metals, stones, etc. Our author retains the Aristotleian classification--earthy, and those of other origin, as beasts, roots, and trees. Earths may be metals or fossils; metal being defined as hard bodies, generated in the earth or in its veins, which can be beaten out by a hammer, and softened or liquefied by heat; while fossils include all other inanimate objects.
A large number of extracts have been made from this part of the subject, because the book gives the position of positive, as distinguished from speculative, Alchemy at the time. It is the Editor’s desire to show that at this period there was a system of theory based on the practical knowledge of the day.
Chemistry took its rise as a science about four hundred years before our era. In the fragments of two of the four books of Democritus we have probably the earliest treatise on chemical matters we are ever likely to get hold of. Whether it is the work of Democritus or of a much later writer is uncertain. But merely taking it as a representative work of the early stage of chemistry, we remark that the receipts are practicable, and some of them, little modified, are in use to-day in goldsmith's shops. The fragments remaining to us are on the manufacture of gold and silver, and one receipt for dyeing purple. In this state of the science the collection of facts is the chief point, and no purely chemical theory seems to have been formed. Tradition, confirmed by the latest researches, associates this stage with Egypt.
The second stage in the history of Chemistry-the birth of Alchemy in the Western World-occurred when the Egyptian practical receipts, the neo- Greek philosophies and the Chinese dreams of an 'elixir vitae' were fused into one by the Arab and Syriac writers. Its period of activity ranges from the to seventh to the tenth centuries. Little is really known about it, or can be, until the Arabic texts, which are abundant in Europe, are translated and classified both from the scholar's and the chemist’s standpoint. Many works were translated into Latin about the end of the tenth century, such as the spurious fourth book of the 'Meteorics of Aristotle,' the treatises of the 'Turba Philosophorum,’ 'Artis Auriferae' etc., which formed the starting point of European speculation. The theoretical chemistry of our author is derived from them.
The third stage of Chemistry begins with the fourteenth and ends with the sixteenth century. It is characterised by an immense growth of theory, a fertile imagination, and untiring ii It reached its height in England about 1440, and is represented by the reputed works of Luly (vixit circ. 1300), which first appear about this date. In this period practical alchemy is on its trial.
The fourth stage begins with Boyle, and closes with the eighteenth century. Still under the dominion of theoretical alchemy, practical alchemy was rejected by it, and its interest was concentrated on the collection of facts. It led up to modern chemistry, which begins with Lavoisier, and the introduction of the balance in the study of chemical change.
Chemical theory then in our author's time stood somewhat thus. Metals as regarded their elemental composition were considered to partake of the nature of earth, water, and air, in various proportions. Fossils, or those things generated in the earth which were not metals, were again subdivided into two classes, those which liquefy on being heated, as sulphur, nitre, etc., and those which do not. The metals were considered to be composed of sulphur and mercury. These substances are themselves compounds, but they act as elements in the composition of metals. Sulphur represented their combustible aspect, and also that which gave them their solid form; while mercury was that to which weight and powers of becoming fluid were due.
This theory was due to two main facts. Most ores of metals, especially
of copper and lead, contain much sulphur, which can be either obtained
pure from them, or be recognised by its smell when burning. This gave rise
to the sulphur theory, while the presence of mercury was inferred doubtless
from the resemblance of the more commonly molten metals, silver, tin, and
lead, to quicksilver. The properties of each metal were then put down to
the presence of these substances. The list of seven metals is that
of the most ancient times-gold, electrum, silver, copper, tin, lead, iron;
but it is clearly recognized that electrum is an alloy of gold and silver.
Most of the facts in this book are derived from Pliny through Isidore,
but that the theory is Arab in origin, one fact alone would convince us.
A consideration of the composition of the metals shows us that tin is nearest
in properties of all metals to the precious ones, but tin is precisely
the metal chosen by Arab alchemists as a starting-point in the Chrysopoeia.
Beside their scientific interest these passages have supplied many analogies. When Troilus is piling up his lover's oaths to Cressida, his final words are:
our chapter on the adamant supplies the origin of this allusion in part, astronomy gives the other. Diamonds are still, unfortunately for the young, the precious stones of reconciliation and of love our author bespeaks them. The Editor has not lengthened the chapter by extracts giving the occult properties of gems, and has contented himself by quoting from the chapter on glass a new simile and an old story.