194 



NATURE 



[July 2, 1903 



was not to Inquire why the animal (or plant) body 

 assumes in its development the characters which it 

 presents to the naturalist, but rather to discover in 

 what processes vital action consists, and to prove that 

 these processes are identical with those of inorganic 

 nature, and can only be investigated by the methods 

 of exact science. But Helmholtz was far from sup- 

 posing that these methods could be applied either to 

 organism and its evolution or to the study of mental 

 processes, and expressed his distrust of the efforts made 

 by others in this direction, with perhaps too great 

 contempt. 



Helmholtz 's professional education began when he 

 left school in 1838, and occupied four years. It is 

 noteworthy that, notwithstanding the almost in- 

 credible amount of work which was imposed on the 

 students of the Pepiniere by a curriculum which not 

 only included anatomy, physiology, pathology, and 

 practice, and the sciences then regarded as ancillary 

 to medicine, but also logic and metaphysics, ancient 

 history, and modern languages, Helmholtz still found 

 leisure for other pursuits. He was not only able to 

 obtain that mastery of music of which he was after- 

 wards to make so splendid a use, but also to pursue 

 without any assistance, except such as he derived from 

 books, the higher branches of mathematics, in the 

 elements of which his schoolmaster (Meyer) had so 

 thoroughly grounded him. 



It need scarcely be said that during this period of 

 ceaseless exertion he became intimate with the greatest 

 of his teachers, J. Miiller, and thus, as he said him- 

 self, had another opportunity of observing " wie 

 die Gedanke selbststandiger Kopfe sich bewegen." 

 This intimacy was, no doubt, of great value to him, 

 but there is no sufficient ground for the conjecture 

 which has often been made that it vi^as from Miiller 

 that he derived his inspiration. The two men were 

 cast in such different moulds that this was scarcely 

 possible. The subject which Helmholtz selected for 

 his Latin graduation essay (" The Structure of the 

 Nervous System in Invertebrates ") was no doubt 

 suggested by Miiller, but Helmholtz was no sooner 

 himself free (" selbststiindig ") than he followed his 

 own bent. It seems probable that, even when he was 

 working assiduously with Miiller as a biologist, he 

 anticipated the direction in which his future studies 

 would lead him, and was already aware that physics 

 and chemistry, not biology, would afford him effectual 

 methods of research. 



Helmholtz graduated in 1842, and soon entered on 

 his duties as a military surgeon. These happily gave 

 him sufficient leisure for his scientific work. His first 

 research, of which the results were published in 

 Wagner's " Handworterbuch," was on the relation 

 between the work done and the heat produced in 

 muscular contraction. It was important as setting 

 forth one of the fundamental facts on which the new 

 science was to be built, and as preliminary to the 

 treatise on the "Erhaltung der Kraft," which appeared 

 two years later. Of the genesis of this work Koenigs- 

 berger gives an interesting account. The introduc- 

 tion to it was written in 1846, the very same year in 

 NO. 1757, VOL. 68] 



which, at the age of twenty-five, he passed his final 

 Staatsexamen as a practitioner of medicine and 

 surgery, his examiners possibly little guessing whom 

 they had before them. The manuscript of the intro- 

 duction was put for friendly criticism into the hands 

 of du Bois-Reymond, who, however, would make no 

 change in it, regarding it as an " historisches Docu- 

 ment fiir alle Zeiten." It was forthwith communi- 

 cated to the recently founded Physical Society of 

 Berlin, the young and active members of which thus 

 became acquainted with the law of the conservation 

 of energy long before it had been discussed by 

 academicians. By the Physical Society it was received 

 with enthusiasm, but when offered to Poggen- 

 dorff for publication in the Annalen, he declined it as 

 being too theoretical, promising, however, to accept 

 it as soon as experimental proofs were forthcoming. 



The four years during which Helmholtz was charged 

 with regimental duties were so productive that, in 

 1849, when a vacancy occurred In the University of 

 Koenigsberg, he was selected by the Minister of Public 

 Instruction among the four whom J. Miiller had re- 

 commended, namely, Ludwig, Helmholtz, du Bois- 

 Reymond, and Briicke, as the men most capable of 

 advancing science in the " physlco-physiological 

 direction." All of these men, whose claims Miiller 

 estimated to be equal, were young, but Ludwig was 

 the senior, and would have received the appointment 

 had not a suspicion of radicalism, wholly unfounded, 

 attached to him. So Helmholtz became, at twenty- 

 eight, professor of physiology with the magnificent 

 salary of 120I. a year ! 



Helmholtz's removal to Koenigsberg was followed 

 by a period of astonishing frultfulness in discovery. 

 The first new subject to which he directed his attention 

 was that of the measurement for physiological pur- 

 poses of extremely short intervals of time, and the 

 application of these methods to the determination of 

 the rate of transmission in nerve. This he accom- 

 plished with such completeness and exactitude that 

 his results can, even now, be accepted without ques- 

 tion. In the meantime he continued those studies in 

 physiological optics which led to the discovery of the 

 ophthalmoscope. This, as well as the subsequent 

 discovery of the mechanism of accommodation of the 

 eye for distance, was communicated to the Physical 

 Society. Then followed an investigation of the time- 

 relations of Induction currents, a research of great 

 importance in the technique of experimental physio- 

 logy. His first researches on colour-vision were pub- 

 lished in Poggendorff's Annalen in 1852, in which 

 journal also appeared, about the same time, another 

 research of great value In Its bearing on electro- 

 physiological questions— an Investigation of the " dis- 

 tribution of currents in bodily conductors. " ^ It was 

 towards the end of the Koenigsberg time that Helm- 

 holtz made his first visit to England. In his letters 

 home he refers with evident pleasure to his intercourse 

 with English physicists, and especially to the im- 

 pression made upon him by Faraday's " herzgewlnn- 

 endes Wesen," and observed with great interest how 

 " old bits of wood and wire " sufficed him for the 



1 See vol. i. p. 177. 



