Its presence in scheelite was detected by Scheele and Bergman in 1781, and in 1783 Juan, Jose and d'Elhuyar showed the same substance occurred in wolfram; they also obtained the metal.
Of the principal workers in this field we may notice Friedrich Hoffmann, Andreas Sigismund Marggraf (who detected iron by its reaction with potassium ferrocyanide, and potassium and sodium by their flame colorations), and especially Carl Scheele and Torbern Olof Bergman.
PRUSSIC ACID, or Hydrocyanic Acid, Hcn, an organic acid first prepared in1782-1783by C. Scheele and subsequently examined by J.
These discoveries of Geoffroy and Scheele formed the basis of Chevreul's researches by which he established the constitution of oils and the true nature of soap. In the article Oils it is pointed out that all fatty oils and fats are mixtures of glycerides, that is, of bodies related to the alcohol glycerin C 3H5(OH)3 i and some fatty acid such as palmitic acid (C 16 H 31 0 2)H.
PYROGALLOL, or Pyrogallic Acid, a trioxybenzene, C 6 H 3 (OH) 3 (1: 2: 3), prepared by Scheele in 1786 by heating gallic acid, C 6 H 2 (OH) 3 CO 2 H.
Only one compound of hydrogen and fluorine is known, namely hydrofluoric acid, HF or H 2 F 2, which was first obtained by C. Scheele in 1771 by decomposing fluor-spar with concentrated sulphuric acid, a method still used for the commercial preparation of the aqueous solution of the acid, the mixture being distilled from leaden retorts and the acid stored in leaden or gutta-percha bottles.
The two great Swedish chemists, Torbern Olof Bergman (1735-1784) and Karl Vilhelm Scheele (1742-1786), flourished at this time.
Incidentally in 1777 Scheele prepared sulphuretted hydrogen, and noted the chemical action of light on silver compounds and other substances.
It was first prepared by C. Scheele and is formed when urea HO C N is treated with water.
The difference between these two latter substances was first pointed out by Cronstedt, and in 1778 C. Scheele prepared molybdic acid from the sulphide.