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ART. V.-1. Hermann Ludwig Ferdinand von Helmholtz. By
JOHN GRAY M‘KENDRICK, M.D. London: T. Fisher
Unwin, 1899. 2. Die Lehre von den Tonempfindungen als physiologische
Grundlage für die Theorie der Musik. Von HERMANN VON HELMHOLTZ. Fünfte Ausgabe. Braunschweig : Vieweg
und Sohn, 1896. 3. On the Sensations of Tone as a Physiological Basis for the
Theory of Music. By HERMANN L. F. von HELMHOLTZ. Second English Edition. By ALEX. J. ELLIS. London:
Longmans, Green & Co., 1885. 4. Handbuch der physiologischen Optik. Von HERMANN VON
HELMHOLTZ. Zweite Auflage. Hamburg : Leopold Voss,
1896. 5. Wissenschaftliche Abhandlungen. Von HERMANN HELM
HOLTZ. Drei Bände. Leipzig : Johann Barth, 1882–1895. 6. Popular Lectures on Scientific Subjects. By HERMANN
VON HELMHOLTZ. Translated by E. Atkinson, Ph.D.
Two Series. London: Longmans, Green & Co., 1898. SEVEN cities competed for the honour of having given
rth to Homer; seven sciences claimed Helmholtz as an expert. So it was somewhat grandiloquently, yet not untruly, said by his panegyrist Engelmann. A rare width of compass belonged, indeed, to that master-mind. Versatile, in the ordinary sense, it was not. The researches of Helmholtz were not varied because of the shifting of the point of interest, but because of the elevation of the point of view. Their succession was by a logical sequence.
De partments of knowledge, ordinarily separated, coalesced before his comprehensive glance. All, he could see, were involved in each; and seeing this, he had scarcely the choice of neglecting any. His powers were adequate to the demands made upon them by the largeness of his intelligence. He could explore in detail, as well as survey from a commanding height. His training, too, helped to amplify his range. A career imposed upon him by necessity not only led on to the career which he would have chosen by preference, but served as a peculiarly fortunate preparation for it, lending volume and strength to the flow of his mental progress. Hermann Ludwig Ferdinand Helmholtz
born August 31, 1821, at Potsdam, where his father, Ferdinand
Helmholtz, taught languages and philology. On the mother's side, he was remotely but remarkably English. Caroline Penne, the wife of the Gymnasiallehrer,' was the daughter of a Hanoverian artillery officer, who traced his descent directly from William Penn of Pennsylvania. Hermann was a sickly child. For seven years his life hung by a thread, and his amusements were his only education. A box of bricks helped to implant geometrical principles; he read much and to the purpose, and special parental care quickened the play of his early thoughts. As he grew older, his father's judicious guidance safeguarded his rising activities against waste or blight. He had a fine memory for what pleased him, but disliked learning prose by rote. Poetry was wisely substituted. Homer and Horace were his favourites among the classics; he could repeat whole books of the Odyssey,' and a number of chiselled Latin odes; he cultivated, as well, German ballad-literature, and his facility for languages is shown by his perusal in Arabic of Lokmân's Fables at the age of twelve. Metaphysical ideas were not wanting. They emerged from certain cloudy symposia where Ferdinand Helmholtz discussed with his colleagues the systems of Kant and Fichte.
At school he astonished his teachers by mathematical intuitions unaccountable by heredity. No scientific leanings were traceable in his family. Spontaneously, too, he turned towards inquiries of the natural' order, seeking the magical 'key' (as he called it) that unlocks the gates of power by the knowledge of law. He devoured superannuated manuals unearthed from dusty bookshelves. He caused much housewifely dismay to his mother by experiments damaging to furniture and linen, he constructed optical apparatus with a few spectacle-glasses and a small botanical lens; and, while Cicero or Virgil was being read by his class at the gymnasium, devoted himself to drawing diagrams under the table, and solving problems relative to the paths of rays in telescopes. To find out the realities of things-this was his passion; and he looked forward, with the secret rapture of early youth, to a life which should be one untiring quest of new truth.
The bread-winning difficulty intervened. He was one of four children. His father, too poor to provide for them, could do no more than put them in the way of providing for themselves. The Friedrich-Wilhelms Institute of Berlin offered free medical education to students promising to take service as surgeons in the Prussian army; a bursarship was
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available for Hermann; he accepted it in 1838, traversed the usual curriculum, and in due course obtained his diploma. Thus his status in the world was fixed for him, not selected by him. He was set upon a level track; his inner promptings were towards untried ways, leading to arduous heights. To these he ultimately attained, never having lost, as Dante once did, la speranza dell'altezza. He aimed throughout at embodying ideal aims in the hard material facts of life; and his history affords a singular example of gradual, almost inevitable reversion to inborn aspirations, not through the neglect, but through the strict fulfilment of duty.
His genius was in truth irrepressible. It possessed a hidden spring of vitality ; like water lying lower than its source, it was always ready to mount to the light. Nor were the surrounding influences wholly adverse. A new breath was just then quickening German university life. The time had come, it began to be felt, to get science out of the rut of a priori conceptions, and on to the rails of definite fact. Hegel and Schelling had borne sway long enough; the fabric of abstract thought which, propped up by their authority, survived the demolition of its foundations, must at length collapse; Berlin could not for ever remain an isolated stronghold of speculation. It was difficult, Helmholtz said in his commemorative address on Gustav Magnus,* to realise in 1871 the state of German science in the first two decades of the century. Recalling his boyish experiences :
'When I began to study physics out of the school-books in my father's possession, I still see before me the dark image of a series of ideas which now seems like the alchemy of the middle ages. Of Lavoisier’s and Humphry Davy's revolutionary discoveries not much had got into the school-books. Although oxygen was already known, yet phlogiston, the fire-element, played also its part. Chlorine was still oxygenated hydrochloric acid ; potash and lime were still elements. Invertebrate animals were divided into insects and worms; and in botany we still counted stamens.'
The permeation of foreign influences brought amendment to this state of things. Researches of the most approved modern type were, one after the other, executed by individual workers on the right bank of the Rhine. Chladni performed his classic experiments on vibrating plates ; Seebeck discovered thermo-electricity in 1821 ; Ohm's law
Popular Lectures on Scientific Subjects, second series, p. 10, 1. 1898
was enounced in 1827; Ritter, Lenz, and Neumann studied fruitfully the characteristics of electric charges and electric currents. But the sense of progress was slow to make itself felt; shadows of the world,' fitting across the fairy mirror of introspection, were more regarded than actual phenomena. A definitive movement of minds set in only with the return from Paris of Mitscherlich, Liebig, and Humboldt. It triumphed conspicuously in Berlin, where Gustav Magnus occupied the Chair of Physics, and Johannes Müller the Chair of Physiology. Among the pupils of the former were Kirchhoff, Clausius, Siemens, and Wiedemann, while those of the latter included Du Bois Reymond, Brücke, and Helmholtz. All united in 1845 to found the Physical Society of Berlin.
an event of no ordinary significance. It marked the uncompromising adoption, by German men of science, of experimental methods. Some even went too far in their exclusive reliance upon them. In the reaction against the syllogism, they were carried to the length of distrusting the calculus. For this, mathematicians themselves were partly to blame. They had attached more importance to the processes of computation than to the soundness of the underlying data, oblivious of the maxim that nothing is taken out of the mathematical mill except what is put into it; the grinding of truth out of error making no part of its function. Hence it came to pass that observation was pitted against reasoning, and sheer empiricism threatened to reign supreme. These exaggerated views were never shared by Helmholtz. His splendid mathematical abilities obtained full play later; they were never wholly in abeyance. His superiority in this respect placed him from the first in a rank apart from his classmates ; and it became more striking as time went on. There was in him a rare faculty of developement; it was impossible to fix the length of his tether. Fulfilment, accordingly, outdid even his brilliant promise.
Less precocious than Clerk Maxwell, he was just twentytwo when he made his first original contribution to research. It resulted from an attack of typhoid fever in the autumn of 1841. As a medical student he was entitled to gratuitous nursing at the Charité Hospital, and on his recovery from the illness he consequently found himself in possession of some savings out of his small resources. He invested them in a microscope, with which he studied the conditions and effects of the presence of vibrions' in saccharine solutions. The upshot was a paper, proving up to the hilt Sch wann's
conclusion, published in 1838, that fermentation, no less than putrefaction, results from the activity of minute living organisms. The experiments described in it demolished Liebig's oxygenation theory ; they all but established Pasteur's final position.
Helmholtz was at this time stationed at Potsdam as assistant-surgeon to the Red Hussars. But his regimental service extended only over a few months. Alexander von Humboldt discerned his quality, and used his influence to procure him scientific occupation. He became in 1843 Professor of Physiology in the Albert University at Berlin, Lecturer on Anatomy to the Academy of Arts, and assistant in the Anatomical Museum. Organic nature seemed destined to engross him; and he was immediately attracted by a problem connected with the very springs of organic life
Stahl's 'soul of life,' rationalised as the 'vital force,' survived essentially in the physiology of that day. Helmholtz had a misgiving,' he tells us,* that there was something against nature in this explanation ; but it took me a good deal of trouble to state my misgiving in the form of a definite question. I found ultimately, in the latter years of my career as a student, that Stahls theory ascribed to every living body the nature of a perpetuum mobile. I was tolerably well acquainted with the controversies on this Jatter subject. In my schcol days I had heard it discussed by my father and our mathematical teachers, and while still a pupil at the Friedrich-Wilhelms Institute I had helped in the library, and in my spare moments had looked through the works of Daniel Bernoulli, D'Alembert, and other mathematicians of the last century. I thus came upon the question, “What relations must exist between the various kinds of natural forces for a perpetual motion to be possible ?” and the further one, “Do those relations actually exist ? ”
He was convinced they did not; but demonstration, not assertion, was needed, and he set himself to supply it. The phenomena of animal heat accordingly invited investigations, in the course of which he invented the 'myograph an instrument for obtaining the characteristic curves of contracting muscles self-inscribed on the blackened surface of a revolving cylinder. But this was, comparatively speaking, of minimal importance; the main outcome was an essay “On the Conservation of Force,' designed merely as an arrangement and criticism of the facts for the benefit of physiologists, but in reality an irreversible pronouncement
* Autobiographical Sketch appended to second series of Popular Lectures on Scientific Subjects,' p. 275.