Makers of Electricity

by Brother Potamian; James J. Walsh

Perhaps the most interesting of Faraday's discoveries, from the scientific standpoint, because they throw so much light on the problems of all the related phenomena of magnetism, heat, light, even electricity, were those in which a ray of polarized light was used as a means of investigating the condition of transparent bodies when acted on by electric and magnetic forces. Faraday himself, when he was just thirty years of age, made a note in his commonplace laboratory book, in which all his observations were carefully detailed, that serves to show how much this subject had begun to interest him thus early in his career. He mentions that he had polarized a ray of lamp-light by reflection, and had made various experiments to ascertain whether any depolarizing action was exerted on it by water placed between the poles of a voltaic battery in a glass cistern, or by various fluids which were decomposed by the voltaic action during the course of the experiment. Besides water, the fluids used were weak solutions of sulphate of soda and strong sulphuric acid. None of them had any effect on the polarized light, either during the passage of the voltaic current or when this was shut off. No particular arrangement of particles in reference to polarized light could be found from these observations.

Such a note, with utter failure for conclusion, is common enough in Faraday's note-book. He was never discouraged, however, by failure at the beginning. Once a subject has been taken up seriously, it is almost inevitable that further observations with regard to it will be found during the course of the year. Because he had asked one question of nature and had not obtained a satisfactory answer, was never a reason why he should not ask further questions along the same line; and, above all, why he should not ask the same question in another way. After having tried a continuous current, Faraday next experimented on the effect of making and breaking the circuit. He did not expect very much from this, but he hoped that under circumstances when no decomposition would ensue as the effect of the current, he might find some indication of the polarization. It was nearly twenty-five years before Faraday succeeded in solving the problem that he had thus set himself as a young man, and nearly twenty years more were to pass before he made the relation between magnetism and light the subject of his very last experimental work. Nothing discouraged him. When he had resolved to investigate something, he continued to make his experiments over and over again in different ways, until finally he got an answer to his question and a solution to the problem.

Indeed, his perseverance in anything that he undertook was a striking characteristic of the man and one of the most important elements in his success in life. His tenacity of purpose showed itself equally in little as in great things. Arranging some apparatus one day with a philosophical instrument-maker, he let fall on the floor a small piece of glass. He made several ineffectual attempts to pick it up. "Never mind," said his companion, "it is not worth the trouble." "Well, but, Murray, I don't like to be beaten by something that I have once tried to do."

Faraday was sure that there was some very definite relation between electricity and light. His experiments, however, did not enable him to demonstrate this until nearly fifteen years after his successful experiment on induction. In September, 1845, he placed a piece of heavy glass made of silico-borate of lead in the field of a magnet, and found that, when a beam of polarized light was transmitted through the glass in the direction of the lines of force, there was a rotation of the plane of polarization. Later experiments showed him that all transparent solids and liquids were capable of producing this rotation in greater or less degree. When no magnet was used and the transparent substance was placed within a coil of wire through which an electric current was flowing, similar effects were produced. This was the demonstration of a definite relation between light and electricity. Later, Faraday found that magnets had a directive action upon the glass. He then made experiments upon gases, and found that they too exhibited magnetic phenomena, and that, indeed, the diurnal variations of the compass-needle were due to the sun's heat diminishing the magnetic permeability of the oxygen of the air. Further experiments with gases showed him that nitrogen was absolutely neutral in its reaction.

It might have been expected, from Faraday's early interest in chemistry, that when he turned to electricity and made discoveries in that field of research, he would naturally take up the problem of tracing the laws and demonstrating the relationships of the points of contact of the two great sciences. After his completion, then, of the subject of induction, Faraday devoted himself to the experimental proof of the identity of frictional and voltaic electricity, and to showing that chemistry and physics have a common ground. His inductive electrical machine could deflect a magnet and decompose iodide of potash. With his tendency to measure things, he determined that the amount of electricity required to decompose a grain of water was equal to 800,000 charges of his large battery of Leyden jars. On the other hand, the current from a frictional machine deflected the needle of his galvanometer in the same way as the induced current of electricity, so that all the elements of the proof of the identity of the two forms of phenomena were now in his hands.

That he should have proceeded to the demonstration of the laws of electrolysis, was the next most natural result. He showed that the amount of any compound decomposed by the electric current is exactly proportional to the whole quantity of electricity which has passed through the electrolyte. Different substances are variously refractory to dissolution under the influence of the electric current, but each one always acts in the same way and requires the same amount of current. Substances that are closely related to one another chemically, are also related to one another in the amount of electricity required to bring about decomposition of their various compounds. He showed, of course, that there are differences of electrical relationship that make the results produced in the decomposition of various compounds very different. Polarization, for instance, sets in to a much greater degree in the decomposition of some substances than of others. One consequence is that the resistance to the passage of the electric current differs markedly, and the opposing electromotive force will stop the current or hamper its effects in many cases, so that, until after actual experiment, the quantitative effect of the passage of the electric current through a solution cannot be determined.

Faraday's opinions as to the significance of electricity in the animal economy are very interesting because of his profound knowledge of electrical phenomena and their place in nature. It is all the more interesting because it is so simple, and most scientists would be apt to say that its very simplicity is a very taking argument for its truth. "As living creatures produce heat, and a heat certainly identical with that of our hearths, why should they not produce electricity also, and an electricity in like manner identical with that of our machines? Like heat, like chemical action, electricity is an implement of life, and nothing more."

While Faraday often occupied himself with subjects connected with matter and force that are likely to remain mysteries for long after his time, and often had thoughts to express with regard to the nature of atoms and of imponderable agents, whatever he had to say about these subjects was not vague and speculative, but, on the contrary, was concrete and usually of such a practical character as to add something new to our knowledge of them. Few men have ever succeeded in getting closer to the mysteries that underlie natural phenomena than Faraday; yet no one was ever less carried away into vague theoretic speculations with regard to them, nor tempted to think that because he knew much more than most other men with regard to complex natural problems, that therefore he knew enough to be able to solve the mysteries that existed all around him. He had none at all of what would ordinarily be called pride of intellect, but, on the contrary, had the humility of the true scientist. Knowing so much only made him realize more poignantly how much he was ignorant of. With regard to his speculations on matter and force and the imponderables, Helmholtz, the great German physicist, once summed up Faraday's contributions very succinctly in a way to show the practical nature of Faraday's intellect. He said:

"It is these things that Faraday in his mature works ever seeks to purify more and more from everything that is theoretical and is not the direct and simple expression of the fact. For instance, he contended against the action of forces at a distance, and the adoption of two electrical and two magnetic fluids, as well as all hypotheses contrary to the law of the conservation of force, which he early foresaw, though he misunderstood it in its scientific expression. And it is just in this direction that he exercised the most unmistakable influence, first of all, on the English physicist, and then on the physicists of all the world."

Inventors and promoters of useful inventions, frequently benefited by the advice of Faraday or by his general help. A remarkable instance of this was told by Mr. Cyrus W. Field. At the commencement of his great enterprise, when he wished to unite the Old and the New World by the telegraphic cable, he sought the advice of the great electrician, and Faraday told him that he doubted the possibility of getting a message across the Atlantic. Mr. Field saw that this fatal objection must be settled at once, and begged Faraday to make the necessary experiments, offering to pay him properly for his services. The philosopher, however, declined all remuneration, but worked away at the question, and presently reported to Mr. Field: "It can be done; but you will not get an instantaneous message." "How long will it take?" was the inquiry. "Oh! perhaps a second." "Well, that's quick enough for me," was the conclusion of the American; and the enterprise was proceeded with.