Natural science in every department developed very wonderfully from its experimental side during the first half of the nineteenth century. Facts and observations accumulated to such an amount that, shortly after the middle of the century, there was felt the need of a great mathematical genius to bring the results of experiment into their proper places in the great body of applied and theoretic science. Nearly always such a demand meets with adequate response in its own due time. Clerk Maxwell came at this most opportune moment for science. No mathematical problem was too abstruse or difficult for him, and whatever he took up seriously he always illuminated, and usually solved its problems as completely as can be hoped for in the present state of scientific knowledge. It was particularly in electricity that his mathematical faculty proved of the greatest value, and that he found the abundant opportunities of which he knew so well how to take advantage.

Clerk Maxwell's theory of electricity, as developed in his classic treatise on "Electricity and Magnetism," is well called by Prof. Peter Guthrie Tait, "One of the most splendid monuments ever raised by the genius of a single individual." This book became the guide and companion of more physical scientists during the nineteenth century than perhaps any other written in that period. It was not alone in England or in English-speaking countries that it was accepted as an authority and constantly referred to, but everywhere throughout the world of science. Not to know it, was to argue that a man knew nothing of the profounder truths of electrical science and was only a seeker after superficial information. Clerk Maxwell was known and esteemed by all the great physical scientists of the world. His name is less widely known than that of most of the great discoverers in electricity, because mathematical achievement always has less popular attraction; but he deserves to be known by all who are interested in science, not only because of his magnificent contributions to mathematical electricity, but quite as much for qualities of heart and mind that stamp him as one of the very great men of the century so rapidly receding from us.

Clerk Maxwell, as he is usually called, because he was the representative of a younger branch of the well-known Scottish family of Clerk of Penicuik, was born in Edinburgh, June 13th, 1831. As with nearly every other person who reaches distinction in after-life, there are stories told of his precociousness which probably have more meaning in this case than in most others, since they exhibit real traits that were characteristic of the man. As a child, it is said that he was never satisfied until he had found out for himself everything that he could about anything that attracted his attention. He wanted to know where the streams of water came from, where and whence all the pipes ran, and the course of bell-wires and the like. His frequently repeated question was, "What's the go o' that." If an attempt were made to put him off with some indefinite answer, then he would insist, "But what's the particular go of it." This was probably the most prominent trait in his after-life. General explanations of phenomena that satisfied other men never satisfied him. He was a nature student from the beginning, and even as a boy he devised all sorts of ingenious mechanical contrivances. Pet animals were his special delight, but for experimental purposes always, and his selection of pets would probably have startled some people.

He received his early education at the Edinburgh Academy, and his university education at the University of Edinburgh, where he graduated in 1850. His liking for mathematics, which had already been very strongly exhibited, led him, at the age of nineteen, to go to Cambridge. Here, for a term or two, he was a student at Peterhouse, but afterwards found a more sympathetic place for his mathematical tastes at Trinity. He took his degree at Cambridge in 1854, though only with the rank of second wrangler, Routh being senior. In the more serious and more exacting examination for the Smith's Prize, he was declared equal with the senior wrangler. His mathematical talents had developed very early, and it is not surprising that the rest of his life should have been devoted mainly to the teaching of mathematics and in investigations connected with applied mathematics. It was not success at the university that determined his career, for he had shown his marvelous mathematical ability much earlier than that, and had given some astonishing examples of his power to treat complex scientific problems in mathematical journals.

Indeed, his original contributions to the higher mathematics began before he was fifteen years of age. He was a striking example of the fact that a great genius usually finds his work very early in life, and usually accomplishes something significant in it, at once the harbinger and the token of the future, before he is twenty-five. While Clerk Maxwell was at the Edinburgh Academy, Professor J. D. B. Forbes, in 1836, communicated to the Royal Society of Edinburgh a short paper by his youthful student on "A Mechanical Method of Tracing Oval Curves" (Cartesian Ovals).

In spite of the prejudice that exists with regard to precocious genius and the distinct feeling that it is not likely to prove an enduring quality, Clerk Maxwell continued to do excellent original work all through his teens. When he was but eighteen, he contributed two important papers to the transactions of the Royal Society of Edinburgh. One of these was on "The Theory of Rolling Curves," and the other on "The Equilibrium of Elastic Solids." These are now remembered, not only because of Clerk Maxwell's subsequent distinguished career, but because of their distinct value as contributions to science. Both of them demonstrate not only his ability to work out subtle mathematical problems at this very early age, but show the possession by him of a power of investigation for original work that stamps them as well worthy of consideration in themselves, quite apart from the repute of their author or the successful accomplishments of his subsequent life.

With regard to one of those Edinburgh papers of Clerk Maxwell's eighteenth year, Prof. Guthrie Tait said "that in it he laid the foundation of one of the singular discoveries of his later life, the temporary double refraction produced in viscous liquid by sheering stress." After his magnificent mathematical training at Cambridge, it is not surprising that this academic career of great original work should be continued by contributions to science of ever-increasing importance. Immediately after his graduation, he read to the Cambridge Philosophical Society one of the few purely mathematical papers that he ever published. This had for its title, "On the Transformation of Surfaces by Bending." Expert mathematicians who read the paper, realized at once that there was a new genius in the field of mathematics. During the same year, the young Scotch mathematician took the first step in that series of electrical investigations which was to occupy so much of his attention in after-life, and which was to prove the source of his greatest inspirations. This consisted of the publication of an elaborate paper on Faraday's "lines of force."

While we think of Maxwell as a mathematical physicist, it must not be forgotten that he was also one of the leading experimental scientists of that great epoch, the nineteenth century. Only a man who was himself a great experimenter could have properly appreciated and developed, from the mathematical standpoint, the works of such men as Cavendish and Faraday. From his early years, Maxwell displayed a distinct fondness for experimentation, and this even extended to experiments upon himself. In many ways this trait of his would remind us of Johann MÜller, the great father of modern German medicine.[31] Like MÜller, there was danger also of Maxwell's experiments on himself getting him into trouble. For instance, at one time his love of experiment led him to try sleeping in the evening and getting up to work at midnight, so as to have the long, silent hours of the night to himself. In the sketch of his life by Dr. Garnett,[32] a letter from one of his friends is quoted with regard to this nocturnal habit, which is amusing as well as interesting. The friend wrote:

"From 2 to 2:30 a. m. he took exercise by running along the upper corridor, down the stairs, along the lower corridor, then up the stairs, and so on until the inhabitants of the rooms along his track got up and laid perdus behind their sporting doors, to have shots at him with boots, hair-brushes, etc., as he passed." His love of fun, his sharp wit, his extensive knowledge, and, above all, his complete unselfishness, rendered him a universal favorite, in spite of the temporary inconveniences which his experiments may have occasionally caused to his fellow-students.

In 1857, Clerk Maxwell received the Adams Prize for his essay on "The Stability of the Motion of Saturn's Rings." He shows very clearly that these annular appendages consist of a large number of small masses. This work would seem to be very distant from anything that Maxwell had attempted before, and would indeed seem to the superficial observer, at least, to be quite out of his sphere. It was the mathematics of it that attracted him, and the fact that the problem was difficult, indeed, one of the most difficult at that time before astronomers, only added zest to his resolve to fathom it. All his life, mathematics continued to be his favorite form of work, and his power to express the most complex physical phenomena in mathematical formulÆ gave him a reputation throughout Europe unsurpassed by anyone of his generation. The more a problem seemed incapable of direct statement in mathematical terms, provided it represented a great occurrence in nature, the more Maxwell was attracted to it; and the training of these early years in thus setting mathematics to the solution of physical relations, was to serve him in good stead when he came to try his hand at demonstrating the meaning of electricity in mathematical terms.

Just before this, in 1856, Maxwell, though only twenty-five years of age, was offered the chair of natural history, which included most of the physical sciences, at Marischal College, Aberdeen. With the attention that his mathematical papers attracted, it is not surprising that after four years of teaching experience he was invited to King's College, London. He held his new position for eight years, and then his health required him to retire to his estate in Kirkcudbrightshire. After three years of retirement, his English Alma Mater demanded his services, and the temptation to get back to an academic career was so great that he could not resist it. He became, in 1871, Professor of experimental physics at Cambridge. To him, more than to anyone else, is due the magnificent development of the physical sciences which took place at Cambridge during the last quarter of the nineteenth century. Unfortunately, he was not destined to live to enjoy the fruits of his labor in organizing the scientific side of the university, but it was under his direction that the plans of the Cavendish Laboratory were prepared, and he superintended every step of the progress of the building. It was under his careful management, too, that the purchase of the very valuable collection of apparatus, with which it was equipped by the Duke of Devonshire, was made, and Maxwell's work here counts for much in the history of English science.

He died in 1879, when only forty-eight years of age, but he had deeply impressed himself upon the science of the nineteenth century. For quite one-half of his scant half-century span of life he had occupied a prominent place in England, and after the age of thirty-five had come to be generally recognized as one of the leading physical scientists of the world. His career is, as we have said, a striking illustration of how early in life a man's real work is likely to come to him, and how little success in original investigation is dependent on that development of mind which is supposed to be due only to long years of application to a particular branch of study. Manifestly it is the original genius that counts for most, and not any training that it receives, except such as comes from its own maturing powers. Environment, if unfavorable, does not hamper it much, nor keep it from reaching the proper terminus of its destiny; and poor health only serves to prevent the exercise of its full powers, but does not eclipse the manifestation of its capacity.

Clerk Maxwell's important contribution to science was the demonstration that electro-magnetic effects travel through space in the form of transverse waves similar to those of light and having the same velocity. We have become so familiar with the ideas contained in this explanation, that they seem almost obvious now. They came, however, as a great surprise to Clerk Maxwell's generation, and at first seemed to be merely a theoretic expression of a mathematical formula. Not long afterwards, however, Maxwell's explanation was corroborated by Hertz, who showed that these waves were propagated just as waves of light are, and that they exhibit the phenomena of reflection, refraction and polarization. Hertz went on from his demonstration of the actuality of Maxwell's mathematical theory to the demonstration of further electrical waves. These Hertzian waves, as they were called, were a startling discovery, but remained only a scientific curiosity until they were taken advantage of for wireless telegraphy, when a new era of applied electrical science began.

How his success in this was accomplished will be best understood from Prof. Guthrie Tait's account of Maxwell's devotion to electricity as a life-work. He says:

"But the great work of his life was devoted to electricity. He began by reading with the most profound admiration and attention the whole of Faraday's extraordinary self-revelations, and proceeded to translate the ideas of that master into the succinct and expressive notation of the mathematicians. A considerable part of this translation was accomplished during his career as an undergraduate in Cambridge. The writer had the opportunity of perusing the MS. on Faraday's lines of force, in a form little different from the final one, a year before Maxwell took his degree. His great object, as it was also the great object of Faraday, was to over-turn the idea of action at a distance. The splendid researches of Poisson and Gauss had shown how to reduce all the phenomena of statical electricity to mere attractions and repulsions exerted at a distance by particles of an imponderable on one another. Sir W. Thomson had, in 1846, shown that a totally different assumption, based upon other analogies, led (by its own special mathematical methods) to precisely the same results. He treated the resultant electric force at any point as an analogous flux of heat from the sources distributed, in the same manner as the supposed electric particles. This paper of Thomson's, whose ideas Maxwell afterwards developed in an extraordinary manner, seems to have given the first hint that there are at least two perfectly distinct methods of arriving at the known formulÆ of statical electricity. The step to magnetic phenomena was comparatively simple; but it was otherwise as regards electromagnetic phenomena, where current electricity is essentially involved. An exceedingly ingenious, but highly artificial, theory had been devised by Weber, which was found capable of explaining all the phenomena investigated by AmpÈre as well as the induction currents of Faraday. But this was based upon the assumption of a distance-action between electric particles, whose intensity depended upon their relative motion as well as on their position. This was, of course, more repugnant to Maxwell's mind than the statical distance-action developed by Poisson. The first paper of Maxwell's in which an attempt at an admissible physical theory of electromagnetism was made, was communicated to the Royal Society in 1867. But the theory in a fully developed form, first appeared in his great treatise on Electricity and Magnetism (1873). Availing himself of the admirable generalized coÖrdinate system of Lagrange, Maxwell has shown how to reduce all electric and magnetic phenomena to stresses and motions of a material medium, and as one preliminary, but excessively severe, test of the truth of this theory has shown that, if the electromagnetic medium be that which is required for the explanation of the phenomena of light, the velocity of light in vacuo should be numerically the same as the ratio of the electromagnetic and electrostatic units. We do not as yet certainly know either of these quantities very exactly, but the mean values of the best determination of each separately agree with one another more closely than do the various values of either. There seems to be no longer any possibility of doubt that Maxwell has taken the first grand step towards the discovery of the true nature of electrical phenomena. Had he done nothing but this, his fame would have been secure for all time. But, striking as it is, this forms only one small part of the contents of his truly marvelous work."

Maxwell's prediction as to the propagation of electric waves has received its full confirmation, as we have said, in the brilliant experiments of Hertz, and in the subsequent application of the Hertzian waves to wireless telegraphy in our own time. It was not by mere chance that this development of Maxwell's thinking came. Hertz himself declared, in the introduction to his collected papers, that he owed the suggestion of his work to Faraday and Maxwell, and above all to Maxwell's speculations as to the nature of electricity and its relations to light. Hertz said:

"The hypothesis that light is an electric phenomenon is thus made highly probable. To give a strict proof of this hypothesis would logically require experiments upon light itself. There is an obvious comparison between the experiments and the theory, in connection with which they were really undertaken. Since 1861, science has been in possession of a theory which Maxwell constructed upon Faraday's views, and which we therefore call the Faraday-Maxwell theory. This theory affirms the occurrence of the class of phenomena here discovered, just as positively as the remaining electric theories are compelled to deny it. From the outset, Maxwell's theory excelled all others in its elaboration and in the abundance of relations between the various phenomena which it included."

How much Maxwell's work was appreciated across the channel, may be realized from what PoincarÉ said: "So sure did the results of his (Maxwell's) theory appear as worked out for the deepest problems, that a feeling of distrust and suspicion is likely to be mingled with our admiration for his magnificent work. It is only after prolonged study and at the cost of many efforts that this feeling is dissipated."Maxwell's explanation of electricity is that it is a strain or stress in the ether, that it is a condition or mode, and not a substance. One distinguished foreign contemporary who had read Maxwell's books with the greatest interest, declared that he could not be quite satisfied, since nowhere did he find what a charge of electricity is, though he seemed to find satisfactory information with regard to everything else. Maxwell realized, however, the limitations of his speculation very well, and hesitated, above all, to bind his mathematical conclusions to statements that might prove eventually only surmises founded on insufficient information from the standpoint of observation. Even when he gave his explanation, he did not insist on it as absolute, but, as pointed out by PoincarÉ, discussed it only as a possibility. The French scientist said: "Maxwell does not give a mechanical explanation of electricity and magnetism; he is only concerned to show that such an explanation is possible."

Maxwell thoroughly believed in having a hobby as well as his regular work, and during the time while he was devoting himself to the mathematical explanation of electricity he turned for recreation to certain problems in physics, in physiology and psychology, relating to color. He worked almost as great a revolution in our knowledge of color-vision as in any other subject that he took up. Principal Garnett has condensed so well what Clerk Maxwell accomplished in the matter of color-vision, in his sketch of him in "The Heroes of Science,"[33] that I prefer to quote his explanation. He says:

"It has been stated that Thomas Young propounded a theory of color-vision which assumes that there exists three separate color sensations, corresponding to red, green and violet, each having its own special organs, the excitement of which causes the perception of the corresponding color, other colors being due to the excitement of two or more of these simple sensations in different proportions. Maxwell adopted blue instead of violet for the third sensation, and showed that, if a particular red, green, and blue were selected and placed at the angular points of an equilateral triangle, the colors formed by mixing them being arranged as in Young's diagram, all the shades of the spectrum would be ranged along the sides of this triangle, the center being neutral grey. For the mixing of colored lights, he at first employed the color top; but instead of painting circles with colored sectors, the angles of which could not be changed, he used circular discs of colored paper slit along one radius. Any number of such discs can be combined so that each shows a sector at the top, and the angle of each sector can be varied at will by sliding the corresponding disc between the others. Maxwell used discs of two different sizes, the small discs being placed above the larger on the same pivot, so that one set forked a central circle and the other set a ring surrounding it. He found that, with discs of five different colors, of which one might be white and another black, it was always possible to combine them so that the inner circle and the outer ring exactly matched. From this he showed that there could be only three conditions to be satisfied in the eye, for two conditions were necessitated by the nature of the top, since the smaller sectors must exactly fill the circle and so must the larger. Maxwell's experiments, therefore, confirmed, in general, Young's theory. They showed, however, that the relative delicacy of the several color sensations is different in different eyes, for the arrangement which produced an exact match in the case of one observer, had to be modified for another; but this difference of delicacy proved to be very conspicuous in color-blind persons, for in most of the cases of color-blindness examined by Maxwell the red sensation was completely absent, so that only two conditions were required by color-blind eyes, and a match could therefore always be made in such cases with four discs only. Holmgren has since discovered cases of color-blindness in which the violet sensation is absent. He agrees with Young in making the third sensation correspond to violet rather than blue. Maxwell explained the fact that persons color-blind to the red divide colors into blues and yellows, by the consideration that, although yellow is a complex sensation corresponding to a mixture of red and green, yet in nature, yellow tints are so much brighter than greens, that they excite the green sensation more than green objects themselves can do; and hence greens and yellows are called yellow by such color-blind persons, though their perception of yellow is really the same as perception of green by normal eyes. Later on, by a combination of adjustable slits, prisms, and lenses arranged in a 'color box,' Maxwell succeeded in mixing, in any desired proportions, the light from any three portions of the spectrum, so that he could deal with pure spectral colors instead of the complex combinations of differently colored lights afforded by colored papers. From these experiments, it appears that no ray of the solar spectrum can affect one color sensation alone, so that there are no colors in nature so pure as to correspond to the pure simple sensations, and the colors occupying the angular points of Maxwell's diagram affect all three color sensations, though they influence two of them to a much smaller extent than the third. A particular color in the spectrum corresponds to light which, according to the undulatory theory, physically consists of waves, all of the same period; but it may affect all three of the color sensations of a normal eye, though in different proportions. Thus yellow-light of a given wave-length affects the red and green sensations considerably and the blue (or violet) slightly, and the same effect may be produced by various mixtures of red or orange and green."

For his researches on the perception of color, the Royal Society awarded Clerk Maxwell the Rumford Medal in 1860.Besides this more or less theoretic work, however, Maxwell made some interesting and important discoveries and inventions in optics. For instance, he noted the great differences that exist in the eyes of dark and fair complexions to different colors when the light falls upon the center of the yellow spot, the so-called fovea centralis, or central pit of the retina. His researches with regard to this led him to the discovery that this portion of the retina is largely lacking in sensibility to blue light. He was able to demonstrate this by his experiment of looking through a glass vessel containing a solution of chrome alum, when the central portion of the field of vision appears of a light red color for the first second or two. He was also the inventor of an ingenious optical apparatus, a real image stereoscope. A still more important discovery was that of the double refraction which is produced for the time in viscous liquids when they are stirred and their motion is not as yet stopped. Maxwell showed that Canada balsam, for instance, when stirred, acquired a distinct power of double refraction, which it retained so long as the stress in the fluid produced by stirring remained.

Other departments of physics were not neglected. For instance, one of his greatest investigations was that on the kinetic theory of gases. Geniuses had been working before him on this line, for, as pointed out by Professor Tait, this theory owed its origin to Daniel Bernoulli, the greatest mathematician of the eighteenth century, and had been developed by the successful labors of Herapath, Joule and, above all, of Clausius. The work of these men put the general accuracy of the theory beyond all doubt and led to its very general acceptance, yet the details of it needed to be elaborated before it could become definitely scientific. Its greatest developments are due to Maxwell, and in this field Maxwell appeared as an experimenter on the laws of gaseous friction as well as a mathematician. His work with regard to color had showed his ingenuity as an experimentalist, and this is still further illustrated by his carefully arranged experiments on gases. Indeed, his work in this line makes it very clear that nothing was too difficult for him, and that anything that he turned his hand to in the field of science he was sure to accomplish with eminent success.

It was not only his scientific monographs, however, that indicate how great a scientist Clerk Maxwell was, but his text-books, even those of more or less elementary character, which he wrote bring out this same idea. He wrote, for instance, an admirable text-book on the theory of heat, which went through many editions. Students of the subject, even those who were not far advanced, found it clear and easier of study than many a less exhaustive work. He also wrote an elementary treatise on matter and motion, which has gone through several editions. One might think that so small a work would scarcely interest him enough to tempt him to put forth his powers at their best, and that at most it would be a conventional condensation of previous knowledge. Prof. Tait, who surely must be taken as a good judge in the matter, says that "even this, like his other and larger works, is full of valuable material worthy of the most attentive perusal not of students alone, but of the very foremost scientific men."

One of the characteristic traits of Maxwell was his desire to impart information to others. This extended not only to his academic relations, but, above all, to the working classes, who might have few opportunities for the obtaining of the information that was so interesting with regard to natural subjects. Everywhere that he held an academic post in his life, he gave lectures to the workmen. He was an extremely interesting talker, and one of his friends said of him: "I do believe there is not a single subject on which he cannot talk, and talk well, too, displaying always the most curious and out-of-the-way information." One of his private tutors said of him: "It is not possible for Maxwell to think incorrectly on physical subjects." It is easy to understand, then, how much his lectures to the working people at Aberdeen, at Edinburgh, and at Kings College, London, as well as at Cambridge, meant for them. If men like Maxwell would take up the popularization of science generally, then there would be much less opprobrium attached to the expression popular science than there has been only too often in the past, and is even at present.

Just as Maxwell set himself to the solution of the most difficult problems in physics, so he did not hesitate to give himself also to the discussion of problems in ethics. Here his power of penetration, the rigid logic of his mind, and his power to follow out conclusions to their ultimate significance, were quite as manifest as any scientific writing. It is almost the rule to find that scientists either ignore the great problems of man's place in nature and his destiny, or treat them very superficially. Agnosticism had become the fad of the moment, and was just beginning to make itself felt as a fashion in thinking when Clerk Maxwell was doing his great work. Maxwell was not an agnostic in science, and because he could not solve all the problems that came to him with regard to electricity and the constitution of matter, this did not keep him from setting himself to the task of seeing what should be his thoughts with regard to these subjects. He had none of the agnostic's feelings with regard to them, that since we cannot know all about them definitely and absolutely, therefore it is not worth while studying them at all. Had Maxwell been tempted to any such line of thought, we would have missed some of the most helpful scientific speculations and suggestions that have ever been made.

No one knew better than Maxwell, that his speculations on matter and electricity were theories, and that what he was offering to science were not definite explanations, but possible hypotheses. He has emphasized this himself over and over again. This inability of the human intellect at the present moment to solve all the questions that its inquiring spirit can evoke, did not keep him from investigating and following up his investigations by mathematical deductions and mechanical suggestions just as far as possible. He had the same attitude of mind toward the great problems of man's relation to his fellow-man, to the universe, and to a hereafter. While he felt that he could not solve the problems entirely, he felt also that his reasoning was quite sufficient to enable him to get a little nearer to the heart mystery of them and to understand something of their significance. In his later years, the question of the existence of pain and suffering in the world had, because of Darwin's attitude towards them and his declaration that since he was unable to understand them they carried him away from the thought of a beneficent Creator, attracted much attention. We have an essay of Clerk Maxwell's, then, on "Aspects of Pain," in which he discusses particularly pain as discipline. It is, of course, the old story, that men rise on stepping-stones of their dead selves, and that the successive deaths of self represent a triumphant progress, but it comes with a new vigor from this great scientist. We all know that it is the man who has suffered who is able to do things, and we are all well aware that the man who has lived in comfort all his life is almost sure to be lacking in character when a great crisis comes upon him. Indeed, as Clerk Maxwell re-states it, this is such a commonplace that one wonders why the problem of pain should have seemed so hard to understand.

There is an essay of his, also, on "Science and Free Will," which seems to deserve special notice. He has no illusions with regard to determinism. He is perfectly sure that he is free and that the great majority of men around him do or do not things as they choose. He points out that science makes for determinism only if one takes a very narrow view of it. Free will is not only compatible with scientific thinking, but it represents what would be expected as a culmination of the significance of life. In a word, Clerk Maxwell wrote as suggestively with regard to the great problems of human life as with regard to the physical nature around him that claimed so much of his interest. He was a true natural philosopher, and his interests were not limited merely to the lower orders of beings.

Because of the supreme power of Clerk Maxwell's mind to seek out the very heart of difficulties, the conclusions which he reached with regard to the existence of matter and the causes for the ultimate qualities which it exhibits, have an enduring interest. Mathematics is sometimes said to lead minds into scepticism. Cardinal Newman even thought that the mathematical cast of mind was the farthest removed from that which might be expected to accept things confidently on faith. Clerk Maxwell's intellect was eminently mathematical; yet, far from sending him over into the camp of the agnostics, his tendency to get at the ultimate reasons for things seemed almost to push him to conclusions with regard to the origin of matter, and especially its ultimate constituents, not ordinarily supposed to be scientific. A passage like the following, for instance, which may be found in his book on "The Theory of Heat," London, 1872, page 312, brings out this tendency very well:

"But if we suppose the molecules to be made at all, or if we suppose them to consist of something previously made, why should we expect any irregularity to exist among them? If they are, as we believe, the only material things which still remain in the precise condition in which they first began to exist, why should we not rather look for some indication of that spirit of order, our scientific confidence in which is never shaken by the difficulty which we experience in tracing it in the complex arrangements of visible things, and of which our moral estimation is shown in all our attempts to think and speak the truth, and to ascertain the exact principles of distributive justice?"

The argument from design for creation is often said in our day to have lost its weight. For Clerk Maxwell, however, this was evidently not the case. On the contrary, he seemed to find in the detailed knowledge of the ultimate constituents of matter which had come in recent years, additional proofs of the great design which permeates nature. He had come to the conclusion that not only were the groups of atoms which make up living things so ordered as to produce definite results, because there was a great purpose and, above all, a great Designer behind nature, but he also reached the position that the separate atoms of matter were so ordered with regard to one another, and in that ordering were so closely related to corresponding qualities in higher beings, that only the presence of a great design in nature could possibly account for all these wonderful attributes, which were to be found even in the smallest portions of matter. He said in his article on the atom, in the ninth edition of the Encyclopedia Britannica:

"What I thought of was not so much that uniformity of result which is due to uniformity in the process of formation, as a uniformity intended and accomplished by the same wisdom and power of which uniformity, accuracy, symmetry, consistency, and continuity of plan are as important attributes as the contrivance of the special utility of each individual thing."

Here is the old argument for the existence of God, from the design exhibited in the universe, rehabilitated by its application to the minutest portions of matter, whose qualities demand such an explanation quite as much as the highest adaptations of nature.

Perhaps the most striking expression of all with regard to the atoms that Clerk Maxwell permitted himself, is that in which he finds the type of what is best in man, in every minute portion of the universe, planted there by the Creator just as surely as they are in His highest beings, because they represent the most precious qualities of His own nature as they are reflected in the creation that He called into existence."They (the atoms) continue this day as they were created, perfect in number and measure and weight, and from the ineffaceable characters impressed on them we may learn that those aspirations, after accuracy in measurement, truth in statement, and justice in action, which we reckon among our noblest attributes as men, are ours because they are essential constituents of the image of Him Who in the beginning created not only the heaven and the earth, but the materials of which heaven and earth consist."

A very interesting side of Maxwell's life is that which shows his continued interest in literature, and even his occasional dippings into poetry. Though he reached distinction in mathematics and physics so early in his career, he yet found time to indulge a liking for the classics, and we even find some rather good translations of Horace's odes from his pen. The translation of a part of the Ajax of Sophocles from the Greek is a striking testimony to the breadth of Maxwell's intellectual interests. All during life, however, he permitted himself occasionally the luxury of fitting words into verse forms, and sometimes with a success that deserves much more than passing interest. It is very probable that the following verses, for instance, which are the first and last stanzas of a poem on the formula for being happy in life and were meant to be sung (or at least so he would hint) to the tune of "Il segreto per esser felice," will strike many a sympathetic chord in the modern time.

There probably was not a more nicely logical or more accurately reasoning intellect among all our nineteenth century scientists than that of the great mathematical electrician. He had none of the one-sidedness of the merely experimental scientist, nor, on the other hand, the narrowness of the exclusively speculative philosopher. With a power of analysis that was seldom equaled during the century, he had a power of synthesis that probably surpassed any of his contemporaries in any part of Europe. His ideas with regard to matter and its ultimate constitution are most suggestive. His suggestion of a strain in the ether as an explanation of electricity, thus enabling scientists to get away from the curious theories of the foretime which had required them to accept "action at a distance," that is, without any connecting medium, shows his power of following out abstruse ideas to definite practical conclusions. His religious life, then, will be a surprise to those who think that science leads men away from religion.

In the life of Clerk Maxwell, written by Campbell and Garnett,[34] there is a passage from his friend and sometime pastor, Guillemard, in which the details of his religious life are given so fully as scarcely to require any further gleaning of information in this regard.

"He was a constant, regular attendant at church, and seldom, if ever, failed to join in our monthly late celebration of Holy Communion, and he was a generous contributor to all our parish charitable institutions. But his illness drew out the whole heart and soul and spirit of the man; his firm and undoubting faith in the Incarnation and all its results; in the full sufficing of atonement; in the works of the Holy Spirit. He had gauged and fathomed all the schemes and systems of philosophy, and had found them utterly empty and unsatisfying—'unworkable' was his own word about them—and he turned with simple faith to the Gospel of the Saviour."

His faith was not disturbed at the near approach of death, but, on the contrary, seemed strengthened. His biographers tell the story of some of the expressions used to his friends during these last days, which furnish manifest proof of this. Some of these passages are so characteristic and so striking that they deserve to be in the note-book of those to whom the modern idea that science is opposed to religion or faith may sometimes have been a source of worry, or at least an occasion for argument. Here is a typical one of these passages:

"Mr. Colin Mackenzie has repeated to us two sayings of his during those last days, which may be repeated here: 'Old chap, I have read up many queer religions; there is nothing like the old thing, after all; and I have looked into most philosophical systems, and I have seen that none will work without a God.'"

It must not be imagined, because Clerk Maxwell was a deeply religious man, that, therefore, he was frigid or formal or extremely serious, or inclined to be puritanic with regard to the pleasures of life, or a fanatic in the matter of taking all the good-natured fun there might be in anything that turned up. He was far from over-serious, or what has been called, though not quite properly, ascetic; but, on the contrary, was often, indeed usually, the soul of the party with which he was at the moment. He had none at all of the self-centered interest of the narrow-minded, but had many friends, and was liked by all his acquaintances. His friends were enthusiastic about his kindness of heart and the thorough congeniality of his disposition. On this point, the sketch of him in the National Dictionary of Biography gives a charming picture:

"As a man, Maxwell was loved and honored by all who knew him; to his pupils, he was the kindest and most sympathetic of teachers; to his friends, he was the most charming of companions, brimful of fun, the life and soul of a Red Lion dinner at the British Association meetings; but in due season brave and thoughtful, with keen interest in problems that lay outside the domain of his own work, and throughout his life a stern foe to all that was superficial or untrue. On religious questions, his beliefs were strong and deeply rooted."

It may be added to this, that his religion had nothing of the merely formal about it, nor was it perfunctory. It entered into most of the details of his life, and the fact that, every day as the head of the house he led evening prayers for the family, was only a token of the deep hold which religion had upon his life. When his last illness came, though he knew that his end was not far off, and at his age sometimes the approach of death hampers religious faith because it does seem that longer life might be afforded to one who has been so faithful in his realization of the obligations of life, Clerk Maxwell's piety increased rather than diminished. A favorite expression of his during his last days was the verselet from Richard Baxter, which one would be apt to think of as frequently repeated by some feminine devotee rather than by the greatest mathematical scientist of the nineteenth century:

A friend who knew him intimately says: "In private life, Clerk Maxwell was one of the most lovable of men, a sincere and unostentatious Christian. Though perfectly free from any trace of envy or ill-will, he yet showed on fit occasions his contempt for that pseudo-science which seeks for the applause of the ignorant by professing to reduce the whole system of the universe to a fortuitous sequence of uncaused events."

In these phases of his intellectual life, the greatest of the mathematical electricians of the nineteenth century deserves to be taken as the type of the man of science, rather than the many mediocre intelligences whose minds were not large enough apparently for the two sets of truths—those of the moral as well as of the physical order.