(b, Riddarhyttan, Sweden, 21 July 1694; d. Stockholm, Sweden, 29 April 1768)
A son of Jurgen Brandt, a mineowner and former pharmacist, and Katarina Ysing, Brandt inherited his father’s interest in chemistry and metallurgy, and as a child was allowed to participate in his father’s experiments in these fields. He continued his studies at Uppsala University and worked for the Council of Mines. Convinced that he needed a more extensive background in the natural sciences, he decided to go abroad. Brandt arrived in Leiden in 1721 and became a pupil of Boerhaave. During three years of intensive study he acquired an extensive knowledge of chemistry, and his medical studies led to the M.D. from Rheims in 1726. On his way back to Sweden he stopped in the Harz Mountains, where he studied mining and smelting, and when he arrived home, he was made director of the chemical laboratory of the Council of Mines. He was named warden of the Royal Mint in 1730. In 1747 he became associate member of the Council of Mines and in 1757 was named a member.
The Laboratorium Chymium Holmiense, where Urban Hiärne had produced his great lifework, had gradually declined because of Hiärne’s advanced age and a lack of funds. When its work was resumed in new offices at the Royal Mint, Brandt’s original contributions and his leadership, as well as the work of his collaborators, Henrik Scheffer and Axel Cronstedt, laid the groundwork for the eminence that Swedish chemistry achieved under such scientists as Bergman, Scheele, and Berzelius. Brandt’s reputation as a chemical experimenter and as a teacher led to an offer of the chair of chemistry (which he refused) when it was established at the University of Uppsala in 1750.
Besides being an able administrator and chief of the laboratory, and making valuable contributions as a chemist, Brandt did outstanding research on arsenic. His findings, published in 1733, constitute the first detailed treatise on various arsenic compounds, their composition, and their solubility in various media. Henckel had begun to analyze the little that was known about arsenic, but Brandt’s research clearly established its metallic nature and proved that white arsenic (arsenious oxide) was an oxide of this metal.
Brandt continued his metallurgical investigations, the results of which he published in a dissertation on semimetals (1735); in addition to mercury, antimony, bismuth, arsenic, and zinc, he dealt with cobalt, which he here showed to be a distinct metal. It is mainly for the discovery of this element that Brandt is known in the history of chemistry. In 1748 he published more findings on cobalt, describing his production of it as a regulus by reducing cobalt pyrite with charcoal, and declaring that it was magnetic.
Brandt also published findings on the difference between soda and potash (1746) and the methods of producing sulfuric acid, nitric acid, and hydrochloric acid (1741, 1743), and the ability of aqua fortis to dissolve gold, provided the gold was alloyed with a certain quantity of silver. In an article on the metallurgy of iron (1751), he proved that thermal brittleness was due to the sulfur content of the iron. However, he stated erroneously that arsenic was the cause of cold brittleness. Before Bergman, Brandt observed that the carbon content of steel was greater than that of cast iron.
I. Original Works. Brandt’s writings are “De arsenico observationes”, in Acta literaria et scientiarum Sveciae, 3 (1733), 39–43; “Dissertatio de semimetallis”, ibid., 4 (1735), 1–10; “De vitriolo albo”, ibid., 10–12; “Acta laboratorii chymici”, in Kongliga Svenska vetenskapsakademiens handlingar, 2 (1741), 49–63; “Continuation”, ibid., 4 (1743), 89–105: “Rön och anmärkningar angäende en synnerlig färg–cobolt”, ibid., 7 (1746), 119–130; “Rön och anmärkningar angående det flyktige alcaliske salter”, ibid., 8 (1747), 301–308; “Nytt rön angående gulds uplösning uti skedvatten”, ibid., 9 (1748), 45–54; “Cobalti nova species examinata et descripta”, in Acta Regiae Societatis Scientiarum Upsaliensis, 1st ser., 3 (1748), 33–41; “Rön och försök angåendejärn, des förhållande mot andra kroppar, samt rödbräckt och kallbräckt jäms egenskaper och förbättring”, in Kongliga Svenska vetenskapsakademiens handlingar, 12 (1751), 205–214; “Några rön och anmärkningar angående köks–salt och dess syra”, ibid., 14 (1753), 295–312 and 15 (1754), 53–68; and Tal om färg–cobolter, hållit för Kongliga vetenskaps academien vid prasidii nedläggande den 30 juli 1760 (Stockholm, 1760).
Some of Brandt’s writings are in Abhadlungen der Königlichen Schwedischen Akademie der Wissenschaften (Hamburg, 1749–1753), and in Recueil des mémoires les plus intéressants de chymie et d’ histoire naturelle, contenus dans les Actes de l’Académie d’Upsal, et dans les Mémoires de l’Acadèmie royale des sciences de Stockholm; publiés depuis 1720 jusqu’en 1760, trans. by Augustin Roux and Paul–Henri, baron d’Holbach, 2 vols. (Paris, 1764).
There are bibliographies of Brandt’s work in Svenskt Biografiskt Lexikon, V (Stockholm, 1925), 788–789; in J. R. Partington, A History of Chemistry, III (London–New York, 1962), 168–169; and Poggendorff, I, 280.
II. Secondary Literature. Works on Brandt are Johan Axel Almquist, Bergskollegium (Stockholm, 1909); and Torbern Bergman, Aminnelsetal öfver Georg Brandt (Stockholm, 1769).