Image: Halliburton. Downhole camera technology puts eyes underground, enhancing a company's understanding of what is going on within the furthest depths of production and helping operators make important decisions that benefit from the all too valuable sense of sight.
Barium was discovered by Sir Humphrey Davy at 1808 in England. Origin of name: from the Greek word barys meaning heavy Baryta (barium oxide, BaO) was distinguished from lime (calcium oxide, CaO) by Scheele in 1774.
In 1878 Swiss chemists Marc Delafontaine and Jacques-Louis Soret observed previously unrecorded spectroscopic lines. They announced the discovery of element âXâ â the element we now call holmium. (1). In 1879 Per Teodor Cleve in Sweden discovered two new materials â one brown and one green â while working with erbia (erbium oxide). The brown substance he named holmia, which he later found to be holmium oxide, and the green substance he named thulia, which is thulium oxide. (2), (2a). Holmium oxide was isolated in 1886 by French chemist Paul Lecoq de Boisbaudran by fractional precipitation.