788 HELMHOLTZ. 



confine myself to an exposition, all too brief, of a few only of the prin- 

 cipal contributions to human knowledge among the great number for 

 which the world is indebted to Professor Helmholtz. It was his dis- 

 tinctive characteristic that among the exponents of modern science he 

 stood quite alone in being really great along several lines. He was in 

 the beginning and always a pure mathematician of high type. Anato- 

 mists and physiologists claimed him for their own. During a few days' 

 stay in New York in 1893, after having presided over the International 

 Congress of Electricians, he was entertained by a distinguished sur- 

 geon, the leading eye specialist of the country, and ophthalmologists 

 flocked to do him honor as one of the founders of their profession. 

 When, in 1881, he gave the Faraday lecture before the Chemical Society 

 of London, the president of the society in presenting to him the Faraday 

 Medal, declared that eminent as was Helmholtz as an anatomist, a 

 physiologist, a physicist, and a mathematician, he was distinctly 

 claimed by the chemists. Nor were these only idle compliments. Only 

 a few days ago I happened on a most curious and interesting illustra- 

 tion of the unequal ed extent of his scientific constituency in finding, 

 in a widely known journal published in London, his obituary notice 

 indexed under the heading, "The stage and music," where his name 

 appeared accompanied by only that of Anton Eubenstein. His great 

 work on the Sensations of Tone and his analysis of the vowel sounds 

 of the human voice gave him a lasting fame among musicians. 



Psychology as well as aesthetics was benefited by his touch, but I 

 think it will be generally admitted that he was first of all, and more 

 than all else, a physicist. Indeed, it may be said that the best fruits of 

 his study of other branches of science grew out of the skill with which 

 he ingrafted upon them the methods of investigation for which we are 

 primarily indebted to the physicist. 



When a boy he had acquired a fondness for the study of nature. His 

 father was a professor of literature in the gymnasium at Potsdam; his 

 mother a woman of English descent. Although he was encouraged in 

 the development of his youthful tastes as much as possible, the neces- 

 sity for earning a living directed his professional studies toward medi- 

 cine and he became a military surgeon. As a physiologist, he was led 

 to the study of " vital force;" his taste for mathematics and physics 

 forced him to the dynamical point of view, and his first great paper, 

 prepared before he was 26 years of age, was on the Conservation of 

 Energy. It is now nearly fifty years since this essay was presented to 

 the Physical Society of Berlin, and doubtless quite fifty years since it 

 was actually worked out. Its excellence is shown by the fact that if 

 rewritten to-day it would be changed only a little in its nomenclature. 

 Fifty years ago the great law of the conservation of energy, which will 

 ever be regarded as the most pregnant and far-reaching generaliza- 

 tion of this century, was so far from being known or recognized that 

 many of the ablest men of the time either regarded it as a " fanciful 

 speculation" — or did not regard it at all. 



