315
INDUSTRIAL A N D ENGINEERINGVHEMISTRY
Jacques Loeb-1859
T
HE life and character of Jacques Loeb were so indissolubly united with his work that they can never be separated. His was one of those rare minds whose fiery quest for the truth brushed aside and subordinated all other interests. It is difficult to think of him otherwise than in his laboratory surrounded by a mass of experimental data or striding up and down as he turned over and over in his mind some difficult problem, inspecting it from all angles in the attempt to find the point which could be subjected to experimental test. The test of direct experiment was one of the striking characteristics of his work. Any suggestion of verbalism or the slightest lack of logical clearness in a discussion or scientific paper would call forth a burst of impatient criticism. It was in devising and carrying out experimental tests of his ideas that his genius reached its greatest heights. He did not believe in conquering an obstacle by laying siege with laborious and painstaking experiments, but preferred to spring upon it from some totally unexpected angle and decide the issue with a simple but marvelously ingenious experiment. To the chemist this method was at times disconcerting. A reviewer of one of his books remarked, “Some of the methods would JACQUES curdle the blood of an analytical chemist.” They furnished results which answered the question, however, and that was to him the essential point. Like Faraday, he had a t times the uncanny gift of knowing the truth before the work was done. He would sometimes say, “I know what it is. The question is, how to prove it.” And yet a single trustworthy experiment would cause him to give up a t once a theory he had upheld with the greatest enthusiasm. An indefatigable worker, for many years he had not rested even a day, from his experiments. His publications of over three hundred papers and many books covered the whole field of biology and extended into chemistry and psychology. Through them all may be traced the love of truth for its own sake and the insistence on a basis of experimental fact. His early training was medical, and his first book, “Brain Physiology,” dealt with the instincts and will from a purely objective and mechanistic viewpoint. It was an attempt to place the philosophy of Diderot and D’Alembert on a scientific basis. The views were revolutionary and were, of course, met with opposition. It is characteristic that he turned to simpler experiments in which there were no disturbing factors. Such material was furnished by the reactions of lower animals to light and other stimuli. Loeb insisted that these responses were purely mechanical and were governed by the ordinary laws of physics and chemistry, and he proceeded to prove this thesis by a series of brilliant experiments. He showed that an animal would go to the light even though i t starved while food lay near it but away from the light. He showed that these animals and plants obeyed the Bunsen-Roscoe law-that if the intensity of the light were doubled half the exposure would bring the same response. These and innumerable other experiments have laid a firm foundation for his “Tropism Theory.” The theory of electrolytic dissociation led him to the belief that the ions are intimately connected with the properties of living matter. The classical experiments on artificial parthenogenesis stand as a monument to the correctness of the idea. He
‘
Vol. 16, No. 3
to 1924
showed in these startling experiments that by suitable treatment with acids and salts certain unfertilized eggs could be caused to develop. In this way the chasm between dead and living matter was partially bridged and a great advance made in the problem to which he devoted his life. Loeb then took up the work on balanced salt solutions. Certain eggs can develop in distilled water and in sea water, but die immediately in a solution of any one salt, even sodium chloride. He worked out in detail the exact relation between the various salts necessary for normal development, and was able to show that it is due to the small amount of calcium in our blood that our muscles do not twitch continuously. But the problem was still too complicated for complete solution, and he turnedggain to a simpler case, the properties of colloids, which resembled in many ways those of living matter. Here again his remarkable experimental ability enabled him to show that a theory derived by Donnan from the laws of classical chemistry sufficed to bring order out of chaos, and it became possible to have a clear, logical explanation for the most striking properties of prtoeins and colloidal solutions in general. SimultaneLOEB ously with this work a long series of intricate experiments on the laws governing regeneration in plants was also led to a successful and simple solution, Nothing could better show his tireless energy and unique ability for experimental work. Like all original workers, Loeb was frequently criticized. His disregard of details and impatience for results left him open to criticism on minor points, while his enthusiasm led him occasionally to venture farther than others were willing to follow. His insistence on quantitative experiments and frequently caustic criticism of anything suggesting verbalism antagonized many of his colleagues. These are minor points and will be forgotten while his work as a whole will always stand as a record of remarkable achievement. But to those who knew him well the man himself stands even above his work; when a t work, a forceful, striking personality, striving with tireless energy after the truth; to his friends a kindly, unassuming gentleman. The same simplicity and directness which qharacterized his work were striking points of his personality. He preferred the simplest equipment for his office and laboratory, and was most a t home in his laboratory a t Woods Hole surrounded by innumerable dishes of sea water in which his experiments were being carried on. Doctor Loeb possessed a charm of manner which was unusual and called forth an immediate response from those who met him. The table a t which he sat at luncheon was always a coveted place, for the conversation was sure to be brightened by some characteristic discussion of current work or by a whimsical elaboration of some quaint idea. To his many younger friends he was a constant source of inspiration and sympathetic advice. They appealed to him all the more readily since his never-failing enthusiasm and idealism kept him always young. JOHN H. NORTHROP. I n honor of the ninetieth birthday of Charles W: Eliot, president e&eritus of Harvard University, a public tribute will be paid him in Cambridge, Mass., on March 20, 1924.
