26 June 1694|
|Died||29 April 1768
|Known for||Discovery of cobalt|
Brandt was born in Riddarhyttan, Skinnskatteberg parish, Västmanland to Jurgen Brandt, a mineowner and pharmacist, and Katarina Ysing. He was professor of chemistry at Uppsala University, and died in Stockholm. He was able to show that cobalt was the source of the blue color in glass, which previously had been attributed to the bismuth found with cobalt. He died on April 29, 1768 of prostate cancer.
About 1741 he wrote: "As there are six kinds of metals, so I have also shown with reliable experiments... that there are also six kinds of half-metals: a new half-metal, namely Cobalt regulus in addition to Mercury, Bismuth, Zinc, and the reguluses of Antimony and Arsenic". He gave six ways to distinguish bismuth and cobalt which were typically found in the same ores:
- Bismuth fractures while Cobalt is more like a true metal.
- In fusing, they do not mingle but attach about as an almond and its stone.
- The regulus of Cobalt fuses with flint and fixed alkali giving a blue glass known as zaffera, sasre, or smalt. Bismuth does not.
- Bismuth melts easily and if kept melted, calcinates forming a yellow powder.
- Bismuth amalgamates with Mercury; the regulus of Cobalt does not at all.
- Bismuth dissolved in nitric acid and with aqua regia and gives a white precipitate when put in pure water. The regulus of Cobalt needs alkalies to precipitate, and then forms dark or black precipitates.
References and notes
- "Georg Brandt". Nordisk familjebok (in Swedish) 3 (2 ed.). 1905. p. 1478. Retrieved 11 November 2010.
- "Georg Brandt". Svenskt biografiskt handlexikon (in Swedish). 1906. Retrieved 11 November 2010.
- "Georg Brandt". Encyclopædia Britannica. Retrieved 14 August 2009.
- "Georg Brandt". Nationalencyklopedin (in Swedish). Retrieved 11 November 2010. (subscription required)
- Regulus: the more or less impure mass of metal formed beneath the slag during the smelting and reducing of ores. Merriam-Webster dictionary
- Gusenius, Edwin M. (1967). "Beginnings of Greatness in Swedish Chemistry: Georg Brandt, (1694-1768)". Transactions of the Kansas Academy of Science 70 (4): 413–425. doi:10.2307/3627593. JSTOR 3627593.