The group 16 elements: the chalcogens

Raoul Pictet ( [link] ) showed that by the evaporation of liquid sulfur dioxide (SO ₂ ), carbon dioxide could be liquefied, which in turn was evaporated to cool oxygen gas enough to liquefy it. Pictet reported his results on December 22, 1877. Two days later, Louis Cailletet ( [link] ) announced his own method of liquefying oxygen. In both cases only a few drops could be produced, making analysis difficult. In 1891 James Dewar ( [link] ) was able to produce enough liquid oxygen to study. However, it was the process developed independently by Carl von Linde ( [link] ) and William Hampson (1854 - 1926).

Sulfur

Sulfur was known in ancient times and is referred to in the Bible. English translations of the Bible commonly referred to burning sulfur as brimstone , giving rise to the name of fire-and-brimstone sermons, in which listeners are reminded of the fate of eternal damnation that await the unbelieving and unrepentant. It is from this part of the Bible that Hell is implied to smell of sulfur (likely due to its association with volcanic activity). Sulfur ointments were used in ancient Egypt, while it was used for fumigation in Greece. A natural form of sulfur known as shiliuhuang was known in China since the 6 ^th century BC. However, it was not until 1777 that Lavoisier ( [link] ) convinced the scientific community that sulfur was an element and not a compound.

Selenium

The element was discovered in 1817 by Berzelius ( [link] ), who found the element associated with tellurium. It was discovered as a byproduct of sulfuric acid production.

Tellurium

Tellurium was discovered in the 18 ^th century in gold ore from the mines in Zlatna, Transylvania. In 1782 Müller von Reichenstein ( [link] ), the Hungarian chief inspector of mines in Transylvania, concluded that the ore was bismuth sulfide. However, the following year, he reported that this was erroneous and that the ore contained mostly gold and an unknown metal very similar to antimony. After three years of work Müller determined the specific gravity of the mineral and noted the radish-like smell of the white smoke evolved when the new metal was heated. Nevertheless, he was not able to identify this metal and gave it the names aurum paradoxium and metallum problematicum , as it did not show the properties predicted for the expected antimony.

In 1789 Kitaibel ( [link] ) also discovered the element independently in an ore from Deutsch-Pilsen which had been regarded as argentiferous molybdenite , but later he gave the credit to Müller. In 1798, the name was chosen by Klaproth ( [link] ) who earlier isolated it from the mineral calaverite.