Helmholtz

A Life in Science

David Cahan

• Éditeur: University of Chicago Press
• Année: 2018
• ISBN:
  9780226549163
• Sujet: Technology & Engineering
• Sous-sujet: Science & Technology Biographies

Hermann von Helmholtz was a towering figure of nineteenth-century scientific and intellectual life. Best known for his achievements in physiology and physics, he also contributed to other disciplines such as ophthalmology, psychology, mathematics, chemical thermodynamics, and meteorology. With Helmholtz: A Life in Science, David Cahan has written a definitive biography, one that brings to light the dynamic relationship between Helmholtz's private life, his professional pursuits, and the larger world in which he lived.
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Utilizing all of Helmholtz's scientific and philosophical writings, as well as previously unknown letters, this book reveals the forces that drove his life—a passion to unite the sciences, vigilant attention to the sources and methods of knowledge, and a deep appreciation of the ways in which the arts and sciences could benefit each other. By placing the overall structure and development of his scientific work and philosophy within the greater context of nineteenth-century Germany, Helmholtz also serves as cultural biography of the construction of the scientific community: its laboratories, institutes, journals, disciplinary organizations, and national and international meetings. Helmholtz's life is a shining example of what can happen when the sciences and the humanities become interwoven in the life of one highly motivated, energetic, and gifted person.

PART I

The Making of a Scientist

1

The Boy from Potsdam

Ancestry

Family stood at the heart of Hermann Helmholtz’s being, so to know something of his family is to begin to know something of him. Throughout nearly all of his life, he was surrounded and supported by family.

Helmholtz’s paternal grandfather, August Wilhelm Helmholtz, was a Prussian government tobacco-warehouse inspector who had married into a family of Huguenot réfugiées (the Sauvage family); to that extent Helmholtz’s ancestry was French. Helmholtz’s father, August Ferdinand Julius Helmholtz, was born in Berlin in 1792 and christened into the Evangelical (i.e., the Lutheran) faith. In the winter of 1807–8, while attending a Berlin Gymnasium and while Prussia was occupied by Napoleon’s forces, Ferdinand heard the philosopher Johann Gottlieb Fichte deliver his highly nationalistic addresses to the German nation. He was deeply moved by these, and he came to hate the French occupier. Shortly thereafter he met Fichte’s son, Immanuel Herrmann Fichte, and the two became soul mates. The elder Fichte’s wife, Marie Johanne Fichte, also became his confidante. In 1811 Ferdinand enrolled in the Theological Faculty of the new, reform-minded University of Berlin and devoted himself to attending Johann Gottlieb Fichte’s classes and learning his philosophical system of transcendental idealism. Fichte’s philosophy remained the intellectual center and inspiration of Ferdinand’s life. Fichte had brought religion back into philosophy, and Ferdinand believed that to understand Fichte’s philosophy required “absolute inspiration and religiosity.” For Ferdinand, Fichte was a man “full of endless sources of deep, Godly wisdom,” one in whom the life of God himself spoke.1 The great attraction of Fichte’s philosophy for Ferdinand thus lay in its religious basis, and therein lay one source of future tension between father and son. In becoming an adept of Fichte, moreover, Ferdinand effectively linked his son to one of Germany’s premier philosophical traditions and one of its principal universities.

Following Napoleon’s setbacks in Russia and his army’s retreat westward, Prussia’s monarch, Frederick William III (1797–1840), called his subjects to fight for the fatherland against Napoleon, and in March 1813 Ferdinand, like most of his fellow university students, withdrew from the university and joined the Prussian militia. He was probably equally moved to do so by Fichte’s lectures of 1812–13; his emphasis on freedom and the role of the state inspired many of his students to rally to the Prussian colors. Ferdinand became a soldier in Prussia’s so-called Wars of Liberation (1813–15) against the French invader, a participant in the nationalist and anti-French movement that swept across Prussia. Stationed in the Silesian mountains (the Prussian monarch had retreated to Breslau), Ferdinand told his “brother” Immanuel Herrmann Fichte that his military duties were dreadfully boring—he worked with cannons and “with the most impoverished people”—but that as long as there was no fighting, army life was something of a vacation. Even so, he hated the constant cleaning and marching, and above all not getting paid; “I certainly want to refresh my weakened body,” he said. Like many other ultrapatriotic Prussians, he also despised the Russians, who, along with the British and the Austrians, were now allied with Prussia against France, and who had destroyed the region: “The Russians are incredibly uncivilized; they are almost like wild nomads (their entire way of fighting still has this character).” He thought little more of the French forces and could not believe that Prussians had run away from the French troops and “surrendered [this] beautiful country to their plundering.” He envied Immanuel Herrmann, who had remained at home, where he could continue his intellectual life and live with his “dear, glorious parents.” He considered himself a “poor devil,” one who “thirsts for salvation” even though he had already “been reborn again.” His fate, he said, lay fully in God’s hands. Two months later, Napoleon defeated the Prussian forces at the Battle of Dresden. Ferdinand retained a lifelong hatred of the French emperor if not of the French in general. Sixty-five years later, Hermann Helmholtz wrote of the men of the Wars of Liberation: “The older ones among us still knew the men of that period: men who had entered into the army as the first volunteers; who were always ready to immerse themselves in the discussion of metaphysical problems; who were well read in the works of Germany’s great poets; and who still burned with anger when Napoleon I, inspiration and pride, and the acts of the War of Liberation were discussed.”2 Hermann inherited Ferdinand’s wartime memories and his attitudes toward the French.

By September 1813 Ferdinand had managed to earn a second-lieutenancy. He planned to return to his university studies, and he asked Johann Gottlieb Fichte what professional course he should pursue. Fichte curtly replied, however, that he should make such a decision himself. After the Treaty of Paris, Ferdinand was released from the army on grounds that he suffered from a chronic, low-level, and unspecified nervous disease. He reenrolled at the university in October, this time to study philology, but he did so only to earn a living: philosophy remained his true passion.3 Yet, after Fichte’s death in 1814, and with his philosophical system now becoming unfashionable—Hegel succeeded him in the chair of philosophy at Berlin in 1818—Ferdinand was left intellectually isolated.

But for moral support and love, he could still turn to “Mother Fichte,” as Fichte’s widow, who was a niece of the poet Friedrich Gottlieb Klopstock and a most pious woman, called herself. While Ferdinand underwent a bathing cure for his bad nerves, “Mother Fichte” worried about his delicate health and instructed him on how to improve it. He hoped her love would aid his healing and “would make him worthy of the great, moral Christian community.” He hoped, too, that he would not become a burden to her, though he knew he would always need her “love and help.” His own family, he explained to “Mother Fichte,” sought to pull him back to its way of life—presumably meaning that of a lower-middle-class, minor government official—“while we individuals [who] develop ourselves further and apart from them have raised ourselves above them.” He felt ashamed and guilt-ridden in telling her this and feared that he had “revealed the picture” of his “confusion, frivolousness, and folly . . . before [her] holy view.”4

After graduating from the university, Ferdinand taught for several years at Berlin’s Cauer Institute, a private secondary school oriented toward the natural sciences. (Among its pupils was Heinrich Gustav Magnus, a future Berlin chemist and physicist, who played a supportive role in Hermann’s professional career.) While the position provided for Ferdinand’s material needs, his emotional state remained fragile. He unburdened himself to Immanuel Herrmann Fichte as someone who “is scared of life,” is afraid to try anything new, who “sees the world timidly and darkly,” and who fears its love and inspiration. Ferdinand felt filled with gloom and condemned a world that would not allow him to fulfill his ideals but, rather, forced upon him “the old concern for existence and pleasure.” His attempts to rise above material existence to higher things had greatly weakened his power, will, and body. In these moments of depression, self-hate, Weltschmerz, and need for redemption—moments that came upon him all too often—he became diffident and filled with self-doubt, self-misery, and self-reproach. He told Fichte, as he had told “Mother Fichte,” of his need to escape from his family, whose “existence and nature is so alien to me.” He wanted Fichte to travel with him to Italy, where he hoped to cure his body and soul. He felt weak, dispirited, and disheartened. He wrote: “You know, it would be the highest goal of my scientific striving if I could once illuminate . . . the history of nature from the higher light of the Wissenschaftslehre [i.e., from Johann Gottlieb Fichte’s theory of scientific knowledge]. It is a matter of action, not scholarship and books.” He hoped God and Italy’s lush environment would inspire his spirit and restore his body. But instead of visiting Italy, he and Immanuel Herrmann had to settle for hiking around Germany and Switzerland until their funds ran out. Ferdinand never saw Italy; and after 1822, when Fichte moved to Saarbrücken, where he became a Gymnasium teacher, he never saw his closest friend again.5

In the autumn of 1820, two events relieved Ferdinand’s depression, at least temporarily. On 1 October he became a teacher at the Potsdam Gymnasium, where, after a probationary year, he remained for the rest of his career. The new job meant more security. The other event was marrying Caroline Auguste Penne.

Precious little is known about Helmholtz’s mother, who was called Lina by Ferdinand and their friends. She was born in Breslau in 1797, the daughter of a Hanoverian artillery officer. Helmholtz himself later declared she was “of an emigrated English family,” and it is widely believed that she descended on her father’s side from William Penn, the Anglo-American founder of the Quaker movement and of the colony of Pennsylvania.6 Yet Helmholtz’s claim, apparently made only once, in 1876, is the only known (written) claim that he ever made to descending from an English family. Moreover, the vast genealogical literature on Penn and his family gives no indication of any connection to Helmholtz’s mother or her possible ancestors. In any case, Lina, like Ferdinand, descended (at least on her mother’s side) from a Huguenot réfugiée family, and, indeed, one whose family name was also Sauvage.

His mother had only a limited formal education, and it appears that her literacy was limited. Her family was without wealth or social position. She was, however, a “sensitive” woman. Immanuel Herrmann Fichte told a mutual friend that his “beloved H.” was in love with “a most worthy and completely admirable girl.” (Lina had also “known and loved” Fichte’s mother.) Though she was not worldly, her soul was of “rare depth and fervor.” Fichte thought the couple very much in love and rightly believed that they would soon marry. On 5 October 1820, four days after his appointment to the Gymnasium, they did so.7

A week later Ferdinand told Fichte that, for once, he was “so happy, so completely ineffably well! For a lovely, holy angel smiles at me always with heavenly joy.” He believed that nothing was greater than “the love of a woman”; “Truly, the angels in heaven cannot be purer, holier, more innocent than the loving wife. . . . With her I want to arise upwards from the Earth and soar up into the eternal spring of another life.” His new job and Lina’s love had saved him; he had (momentarily) found heavenly bliss on earth, which included Lina’s excellent terrestrial (read: domestic) skills.8 These she now exercised in their new home in Potsdam.

Potsdam

The city of Potsdam lies immediately southwest of Berlin, encircled by a chain of picturesque, forested hills surrounding the sandy, damp Havel river and valley. Its magnificent lakes, which were unspoiled territory, and its proximity to Berlin made it an ideal location for the Prussian monarch’s country residence as well as for many nobles. For the Hohenzollerns and their entourages, Potsdam was to Berlin what Versailles was to Paris for the Bourbons: a royal palace and park (Sanssouci), and a second residence for the king. But it was also a garrison city: it housed Prussia’s military headquarters and was filled with soldiers. Potsdamers saw the Prussian state and military up close. They knew, too, the city’s splendid gardens, its botanical school, and its Nikolaikirche and Garnisonkirche, two of its principal landmarks. It was home to numerous Huguenot descendants, many of whom had settled near the city’s center, the Wilhelmsplatz, giving Potsdam a touche française.9 See figure 1.1.

Yet the Napoleonic Wars had greatly damaged Potsdam’s economy, and it took nearly two generations—including nearly all of Helmholtz’s youth—for the city to fully recover. Napoleon’s troops forced the Prussian high command and its army to abandon the city, and for two years (1806–8) he quartered his troops there and generally ravaged the city. Local industries were shut down, and depression ensued. Though the Prussian army returned, industry crept back only slowly, and the recovery remained limited in scope. The city did grow from about twenty-one thousand (in 1821) to about thirty-one thousand (in 1849), but the poor were as present as the king’s soldiers. Although the construction of several villas during Frederick William III’s reign brought some economic benefits, the city’s poverty increased and its industry and trade remained at low levels until 1850.

On the other hand, Potsdam was also home to numerous civil servants. The monarchy and its retinue did much to shape the city. Frederick William III induced Karl Friedrich Schinkel, Prussia’s premier architect, and Peter Joseph Lenné, its premier landscape architect, to help renovate Potsdam, and together they transformed the city’s appearance. After 1826 Schinkel rebuilt the Nikolaikirche, and it became the city’s architectural focal point. When Frederick William IV (1840–61) assumed power, he lavishly enhanced Potsdam’s parks, gardens, and landscape and sought to give them an Italian flavor. Moreover, in 1832 an optical telegraph was built on Potsdam’s Telegrafenberg, linking various parts of Prussia with one another and with Potsdam and making the latter into something of a Prussian communications center. The telegraph line and the Berlin-Potsdam railway line (opened in 1838) became symbols of modernity. While Potsdamers continued to experience economic hard times, the monarchical and governmental presence, and the spending on public goods and services, helped the city to recover.10

Fig. 1.1 Friedrich August Schmidt, Potsdam vom Babelsberg, 1830/40. Horst Drescher and Renate Kroll, Potsdam aus drei Jahrhunderten (Weimar: Hermann Böhlaus Nachfolger, 1981), Nr. X.

Potsdam’s liberal, middle-class citizenry also helped the city to develop culturally. Many of them joined voluntary associations (Vereine) devoted to various public and private causes. Among them was the Potsdam Art Association (Kunstverein), founded in 1834 by Wilhelm Puhlmann, a military doctor and friend of the Helmholtzes. Puhlmann became a leading art collector and an important figure in promoting the arts in the Berlin region; he was a very close, lifelong friend of the painter Adolph von Menzel. Moreover, Puhlmann and Ferdinand Helmholtz were both active in Potsdam’s Peace Society (Friedensgesellschaft), a civic organization that provided stipends to help support impoverished but talented youths in the Berlin-Potsdam region who wanted to study art.11

In short, the Potsdam in which Helmholtz was born and raised was at once a royal, military, civilian, and artistic center seeking to recover from the devastation of the Napoleonic Wars, a city whose surrounding natural beauty, small population, struggling economy, and art and architecture all contributed to his sense of Heimat.

Family and Early Childhood

Home for the newlywed Helmholtzes was a house at Wilhelmsplatz 14. It was here, on 31 August 1821, that Lina bore the first of their six children: Herrmann Ludwig Ferdinand Helmholtz. The first of Helmholtz’s three Christian names was the most Germanic one, symbolizing both German military strength and unity; he owed that name to Ferdinand’s love of his “brother,” Immanuel Herrmann Fichte. (Until Helmholtz’s medical-school years, he usually spelled it with two r’s; only then did he drop the archaic for the modern form.) His second name he owed to Christian Ludwig Mursinna, an elderly great-uncle and the surgeon general of the Prussian army. His third name, given at Lina’s insistence, he owed to Ferdinand himself. With these three Christian names his parents sought to give him a sense of tradition, family, and honor and so to shape his identity. As for his surname, it derived from an ancient Germanic name, perhaps Helmbold or Helmhold. Like his parents, he was christened into the Evangelical (Lutheran) faith; on 7 October, he was baptized at the Holy Ghost Church (Heilig-Geist-Kirche), with no fewer than twenty-three godparents present.12 From the outset of his life, and indeed throughout its entirety, family surrounded and protected him.

In the weeks following his birth, he gave his mother “unspeakable pains” during breastfeeding. (Much later in life, he turned this intimate physical act into an epistemological point in favor of his empiricist theory of perception, declaring that breastfeeding was a learned act on the newborn’s part.) He gave his father, who as usual felt overworked and filled with “care and anxiety,” much pride. Ferdinand wrote Fichte that the latter’s godson was growing “healthier and stronger daily.” He was his father’s “Man-Son, a true little giant, as everyone says, and beyond the level of intelligence for his...