WILLARD GIBBS

PHYSICIST

1839-1903

BY EDWIN E. SLOSSON

BACON says there are two kinds of men of science, the ants and the spiders. The ants are the men of experiment who collect facts and use them. The spiders are the men of theory who spin cobwebs from their own minds. He condemns both extremes, and, thanks in part to his exposition of the need of combining theory and practice, the two species are becoming less distinct. The practical man is more and more recognizing the importance of theory, and the theorist is paying better heed to experimentation. Nevertheless, the two mental types persist, and it is usually possible to tell to which any scientist, however great, inclines. The practical man uses a general law as a vaulting-pole to assist him in jumping from one fact to another. The theoretical man uses facts as stepping-stones to reach a general law. The practical man receives his inspiration from mixing with men and perceiving their needs. He produces immediate results and he gets an immediate reward in popularity, praise and wealth. The nature of his work is apparent to everybody, and his achievements are appreciated, indeed often overestimated, by his contemporaries. The theorist, on the contrary, is heard of more often after his death than during his life, for he is apt to be something of a recluse, following his own thread of thought without allowing his attention to be distracted by the shouts of the crowd who cannot understand his work or his temperament, and are always calling him in directions that to them seem more profitable.

Of American scientists Count Rumford and Prof. Willard Gibbs, are the best examples of these two tendencies, and since each was able to make his life the expression of his personality in a very unusual degree, they form as remarkable a contrast in life as in temperament. The former was a man of the court, the latter of the college. The one was a rover, an adventurer, whose changes of fortune would form a theme for a romance; the other lived a cloistered life, absolutely devoid of dramatic incident, the intellectual life in its purest form. Rumford took great delight in the honors, decorations and titles heaped upon him as he journeyed from country to country, and the applause of street crowds was sweet to his ears; the influence of women was a potent factor in his life. Gibbs was shy and modest, a celibate, and was little known personally except to some of his colleagues of the faculty. Anyone of ordinary culture can read understandingly all of Rumford's papers. Gibbs' work is a sealed book to all but a few of mathematical mind and training.

Rumford's work had always a practical purpose, even when he was evolving a general law, and he hastened pèrsonally to apply the scientific principles he discovered to the conveniences of daily life. Gibbs paid no attention to the invention of useful articles, or to the promotion of manufactures. Rumford used general principles as guides to his further experimentation; Gibbs left entirely to others the experimental verification of the laws he logically deduced. Rumford carried on researches of the most varied character; Gibbs confined his life-work to a few closely allied studies. Rumford's discoveries were the result of his alert observation and shrewd wit; Gibbs made his deductions by slow and sure process of rigid mathematical analysis.

It would be useless to discuss which type of scientist is the more useful, and it would be unjust as well as futile to blame the one for not being the other. We do not find fault with a great general because he is not also a great poet, and there is need for as wide a diversity of gifts in the advancement of science. The theorist and the utilitarian often fail to understand and to appreciate one another; such narrowness cannot be ascribed to the two men here

contrasted, for in their case it was a concentration of personal powers, not a narrowness of mind that made their work so diverse. Gibbs did not despise applied science, nor did Rumford neglect theory. Each did most what he could do best, the work he was fitted by nature to do, and what, in the state of science at the time, was most needed. In the days of Rumford, when physical science was in its infancy, one who devoted himself to its prosecution had to justify such research by constantly showing its value to mankind. Experiments had to be crude because facilities were lacking. But in the time of Gibbs, a hundred years later, the technique of experimentation had reached great perfection, the usefulness of scientific research had been demonstrated, and there were plenty of workers in well-equipped laboratories, but deep abstract thinkers were rare. Ants were numerous and busy, but spiders were hard to find.

Chemistry is in a peculiar state. It started as a practical science and its advance has been so rapid that the theoretical has never caught up with it. By a century of very successful experimental work there have been accumulated a larger number of verified facts than was ever before at the disposal of a science, but there is an almost complete lack of guiding theories and correlating hypotheses. Hundreds of thousands of chemical compounds have been made and studied; their melting-points, boilingpoints and solubilities have been determined; their properties and reactions are known; but why they look and behave as they do no one can tell. The chemist who mixes together two compounds can guess only by means of vague and uncertain analogies how they will act. Whether a given salt will be more or less soluble in hot water than in cold, whether two solutions of salts when mixed will precipitate a solid, evolve a gas or remain unchanged he has no way of determining for sure except to try and see.

A successful chemist needs the memory of a politician; he has to exert himself continually to enlarge his circle of acquaintances, and to remember as much as possible about their behavior under all circumstances. He envies his brother physicist, who needs only carry in his head a neat little collection of formulas to be able to