TITIUS (TIETZ), JOHANN DANIEL

(b. Konitz, Germany [now Chojnice, Poland], 2 January 1729; d. Wittenberg, Germany, 16 December 1796)

astronomy, physics, biology.

Titius was the son of Barbara Dorothea Hanow, the daughter of a Lutheran minister, and Jacob Tietz, a draper and Konitz city councillor. His father died when he was young, and Titius was sent to Danzig to be brought up by his maternal uncle, the natural historian Michael Christoph Hanow, who enouraged his interest in natural science. Titius finished his studies at the Danzig grammar school, then, in 1748, entered the University of Leipzig, from which he received the master’s degree four years later with a dissertation on Euler’s theory of moonlight. In 1755 he became a private lecturer in the Leipzig Faculty of Philosophy; in April 1756 he accepted an appointment as professor ordinarius for lower mathematics at the University of Wittenberg. In 1762 Titius became professor of physics and Senior of the Faculty of Philosophy at Wittenberg, while in 1768 he was appointed rector of the university. In addition to his courses in mathematics and physics, he also lectured on philosophy, natural theology, and natural low.

Titius was a versatile and industrious man who mastered the natural science of his time without making any significant original contribution to it. Although he only occasionally devoted himself to astronomy, he became famous chiefly for the law–now named for him–governing the distances between the planets and the sun, a law that he may have formulated without making observations. Titius’ law was first stated in the 1766 translation of Charles Bonnet’s Contemplation de la nature, published in Leipzig, and appeared as a note to a number of subsequent editions of this work. It states that the distances between the planets and the sun are laid down in the sequence

A = 4 + 2ⁿ · 3 (n = –∞, 0, 1, . . ., 4).

In 1772 this was confirmed by Bode, who placed a hypothetical planet between Mars and Jupiter, in the space that Titius had reserved for a satellite of Mars; it was in this spot that Ceres, the first planetoid, was discovered by Piazzi in 1801. Titius’ law is accurate in accounting for the average distances between the planetoids and the sun and is also true for the planet Uranus, discovered by Herschel in 1781; it is, however, absolutely wrong for both Neptune and Pluto.

Titius’ chief scientific activity was directed to physics and biology. He published a number of works on physical topics, including a set of conditions and rules for performing experiments. He was particularly concerned with thermometry; in 1765 he presented a survey of thermometry up to that date, with emphasis on the air thermometer, and also wrote a monograph on the metallic thermometer that had been constructed by Hanns Loeser in 1746–1747. In addition, Titius wrote treatises on both theoretical and experimental physics, in which he incorporated the findings of other workers (as, for example, the descriptions of experiments written by Georg Wolfgang Kraft in 1738).

Titius’ biological work was influenced by that of Linnaeus. His most extensive publication on the subject, Lehrbegriff der Naturgeschichte Zum ersten Unterrichte (Leipzig, 1777), is a systematic classification of plants, animals (based in part on the system of Jacob Theodor Klein), and minerals, as well as the elemental substances ether, light, fire, air, and water. In shorter works dealing with the classification of animals (1760) and minerals (1765), Titius attempted to emend Linnaeus’ method. He also devoted two other short monographs to specific subjects, the penduline titmouse (1755) and a method for preventing the silting of the split near Danzig by planting acacias, seaweed, and broom (1768).

A number of Titius’ other publications are devoted to questions of theology and philosophy as they pertain to science. He also wrote historical works, including a history of West Prussia and Wittenberg, a description of the conquest of West Prussia by Kasimir IV of Poland in 1454–1466, and, on the occasion of the building of a new bridge across the Elbe, a historical survey of earlier bridges at that spot.

Titius was further prominent as the editor of six series of periodicals chiefly concerned with natural science. These were written for the purpose of making new scientific results known to specialists and non-specialists alike and were also designed to entertain; for this reason they achieved considerable popularity. Among them, the Allgemeines Magazin was limited to translations of works by foreign authors, while Titius himself contributed articles to the Neue Gesellschaftliche Erzählungen and wrote fourteen of the thirty-two articles printed in the Gemeinnützige Abhandlungen, which dealt mainly with the natural history of Saxony. In his efforts to make foreign scientific writings available to the greatest number of readers, Titius was also active in promoting cheap reprints of important segments of the Philosophical Transactions of the Royal Society.

Although he was offered chairs in other universities, including those of Göttingen, Helmstedt, Danzig, and Kiel, Titius chose to spend forty years at Wittenberg. His son, Salomo Konstantin Titius, also taught at Wittenberg, where he held the third chair of medicine, which embraced anatomy and botany, from 1795 until his own death in 1801.

BIBLIOGRAPHY

1. Original Works. The most detailed bibliography of Titus’ writings is Johann Georg Meusel, Lexikon der vom Jahre 1750–1800 verstorbenen teutschen Schriftsteller, XIV (Leipzig, 1815), 74–81. See also Poggendorff and the extensive lists given in Neues gelehrtes Europa, pt. 19 (Wolfenbüttel, 1773), 630–642; J. F. Goldbeck, Litterarische Nachrichten von Preussen, pt. 1 (Leipzig-Dessau, 1781), 194–200; and F. C. G. Hirsching, Historisch-litterarisches Handbuch berühmter und denkwürdiger Personen, welche in dem 18. Jahrhundert gelebt haben. fortgesetzt und herausgegeben von J. H. M. Ernesti, XIV (Leipzig, 1810), 375–376, all of which also give brief biographical notes. An autobiographical note is in Nachricht von den Gelehrten, welche aus der stadt Conitz des Polnischen Preussens herstammen (Leipzig, 1763), 69–74, which also contains Titius’ own catalogue of his writings up to that time. His own list of writings up to that time 1773 is available in the Universitäts-und Landesbibliothek Sachsen-Anhalt, Halle.

Titius’ monographs include Luminis lunaris theoria nova, argumentis Euleri superstructa (Leipzig, 1752); Investigatio finium divinorum in rebus naturalibus necessaria, adversus Cartesium Princip, philos. 1.28. 111.2 defensa (Leipzig, 1753); Philosophische Gedanken von dem Wahren Begriffe der Ewigkeit—Eternity is All! (Leipzig, 1755); Parus minimus Polonorum remiz Bonoiensium pendulinus descriptus (Leipzig, 1775); Feyerliches Denkmahl der Ehrfurcht und Treue, dem glorreichen Gedächtnisse Friedrich August’s, Königs in Polen, und Kurfürst Friedrich Christian’s gewidmet von der Teutschen Gesellschaft in Wittenberg (Wittenberg, 1763); Attributorum Dei, apto digestorum ordine, brevis expositio (Leiden, 1763); Ortus mundi necessarius a priori assertus (Wittenberg, 1763); Thermometri metallici ab inventione illustrissimi atque excellentissimi S.R.I. Comitis Loeseri descriptio (Leipzig, 1765); Die gänzliche Ergeburg der Lande Preussen an Polen, mittelst des A. 1466, nach der Einnahme von Comitz, zwischen König Casimir dem IV und dem Hohmeister Ludwig von Erlichshausen geschlossenen Friedens, historisch vorgestellet (Wittenberg, 1766); Abhandlung über die von der naturforschenden Gesellschaft in Danzig aufgegebene Frage: Welches die dienlichsten und am wenigsten kostbaren Mittel sind, der überhandnehmenden Versandung in der Danziger Nähring vorzubeugen und dem weitern Anwachs der Sanddünen abzuhelfen (Leipzig, 1768); Physicae dogmaticae elementa, praelectionum causa evulgata (Wittenberg, 1773) Lehrbegriff der Naturgeschichte zum ersten Unterrichte (Leipzig, 1777); Grundsätze der theoretischen Haushaltungskunde zum Unterrichte der Anfänger und zur fernern Erklärung entworfen (Leipzig, 1780); Physicae experimentalis elementa praelectionum causa in lucem edita (Leipzig, 1782); and Nachricht von der vormaligen und der neu erbaueten Elbbrücke bey Wittenberg nebst einigen Beylagen mitgetheilet (Leipzig, 1788).

The periodicals edited and in part written by Titius are Allgemeines Magazin der Natur, Kunst und Wissenschaften, 4 pts. (1753–1754); Neue Erweiterungen der Erkenntnis und der Vergnügens, 12 vols. (1753–1762); Neue Gesellschaftliche Erzählungen für die Liebhaber der Naturlehre, der Haushaltungswissenschaft, der Arztneykunst und der Sitten, 4 pts. (1758–1762); Wittenbergisches Wochenblatt zur Aufnahme der Naturkunde, und des ökonomischen Gewerbes, 8 volS. (1768–1775); Gemeinnützige Abhandlungen zur Beförderung der Erkenntniss und des Gebrauches natürlicher Dinge in Absicht auf die Wohlfahrt des Staates und des menschlichen Geschlechts überhaupt, pt. 1 (1768); and Nüttzliche Sammlung von Aufsätzen und Wahrnehmungen über die Witterungen, die Haushaltungskunde, das Gewerbe, die Naturkenntniss, Polizey und andere damit verknüpfte Wissenschaften, als die Fortsetzung des Wittenbergischen Wochenblatts, 10 vols. (1783–1792).

II. Secondary Literature. In addtion to the biographical notes in the bibliographies cited above, see the brief notice by R. Knott, in Allgemeine deutsche Biographie. A portrait of Titius, engraved by S. Halle, is at the beginning of J. G. Krünitz, Oeconomische Encyklopädie, XLV (Berlin, 1789). See also M. M. Nieto, The Titius-Bode Law of Planetary Distances: Its History and Theory (Oxford, 1972).

Menso Folkerts