Note 49 bis — Chapter XI · THE HALOGENS: CHLORINE, BROMINE, IODINE, AND FLUORINE
George Kamensky translation
T. Nikolukin (1885) and subsequently Friedrich and Classen obtained PbCl4 and a double ammonium salt of tetrachloride of lead (starting from the binoxide), PbCl42NH4Cl; Hutchinson and Pallard obtained a similar salt of acetic acid (1893) corresponding to PbX4 by treating red lead with strong acetic acid; the composition of this salt is Pb(C2H3O2)4; it melts (and decomposes) at about 175°. Brauner (1894) obtained a salt corresponding to tetrafluoride of lead, PbF4, and the acid corresponding to it, H4PbF8. For example, by treating potassium plumbate (Chapter XVIII. Note 55) with strong HF, and also the above-mentioned tetra-acetate with a solution of KHF2, Brauner obtained crystalline HK3PbF8—i.e. the salt from which he obtained fluorine.