Johann Gottfried Berger

Background

Johann G. Berger was born on November 11, 1659, in Halle (Saale), Germany, the son of Valentin Berger, an important educator of the mid-seventeenth century.

Education

Berger studied mathematics and medicine at Jena from 1677 to 1680, chiefly under Georg Wolfgang Wedel, a physician who was especially interested in iatrochemistry. At Jena, Friedrich Hoffmann and Georg Ernst Stahl were among his fellow students.

After a brief period at Erfurt, Berger returned to Jena and graduated in 1682 with a thesis entitled De circulatione lymphae et catarrhis. In connection with this work, he traveled through France, Italy, and perhaps Holland.

Career

From 1684 to 1688 Berger worked at the University of Leipzig with Johannes Bohn, who influenced Berger to develop a critical attitude toward iatrochemistry. Berger wrote two dissertations at Leipzig: De mania (1685) and De chylo (1686).

From 1688 until his death Berger worked at the University of Wittenberg; first as assistant professor and from 1689 as third-ranking professor of anatomy and botany. He celebrated his appointment to the latter with an inaugural address in the spirit or natural theology.

In 1693 Berger assumed the chair of pathology, and in 1697 Friedrich August I, king of Poland and Saxony, appointed him physician in ordinary. From 1730 he was the consiliarus aulae, that is, the senior of the entire university. Johann G. Berger died on December 2, 1736, in Wittenberg, Saxony-Anhalt, Germany.

Achievements

• Johann Gottfried Berger is remembered a professor at Wittenberg, physician to the king of Poland and the elector of Saxony, who studied iatromechanics and wrote about fifty treatises.

Views

Berger tended heavily toward iatromechanics and the corpuscular theory of Descartes, whom he often quoted. The body is a natural machine connected with an immortal soul (mens is substantia cogitans; corpus is substantia extensa) and united harmoniously by divine design.

Berger also discussed extensively the circulation of the blood and argued that the flow of blood and the nerve fluid determine the rhythmical activity of the heart. He considered the arteries to be elastic, as Giovanni Borelli had suggested. Berger described several experiments involving the injection of mercury and colored liquids into the blood vessels. He attributed body heat to the rapid movement of those fine particles mentioned by Descartes. It originates in a heavenly material and not in the calor innatus, as the ancients had suggested. Berger confirmed the circulation of blood by exsanguinating a dog within a few minutes, and he determined the total amount of blood.

Berger dealt very thoroughly with the function of nerves: they are porous and conduct a fluid that is distributed by arterial blood pressure from the brain by way of the nerves to the periphery. There is neither a spiritus animalis nor are there the facultates or archei of ancient physiology. Berger rejected the explosion theory of muscle contraction proposed by William Thomas and Borelli, stating that the intellect controls the nerve fluid during voluntary motions. The soul resides in the corpus callosum, not in the pineal gland. The soul did not, as Stahl maintained, influence the activity of the internal organs.

Berger also stated that complete section of the vagus nerve is not immediately followed by death, but only after some days; breathing does not serve to cool the blood, but to restore and refine it by means of contact with the air.

In addition to all, Berger was an opponent of all obscurity; he fought against the weak points of the Galenists and Paracelsians, as well as against the students of Stahl.

Membership

In 1690, Johann G. Berger was elected an academician of the Academy of Sciences Leopoldina.

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  Academy of Sciences Leopoldina , Germany

  1690

Personality

Johann G. Berger was very well read, and very critical.

Connections

Father:

Valentin Berger

Brother:

Johann Wilhelm Berger

Brother:

Johann Heinrich Berger