‎"WOLLASTON, WILLIAM HYDE. - THE DISCOVERY OF THE ELEMENT RHODIUM.‎
‎On a new Metal, found in crude Platina. Read June 24, 1804.‎

‎(London, Bulwer and Co., 1804). 4to. Without wrappers as extracted from ""Philosophical Transactions of the Royal Society of London."" Year 1804-Part II. Pp. 419-430. Clean and fine.‎

Reference : 42469

‎First appearance of the paper in which Wollaston announced his discovery of the metallic element Rhodium.""Dr. Wollaston dissolved a portion of crude platinum in qgua regia, and neutralized the excess acid with caustic soda. He then added salammoniac to precipitate the platinum as ammonium chloroplatinate, and mercurous cyanide to precipitate the palladium as palladium cyanide. After filteringoff the precipitate, he decomposed the excess mercurous cyanide inthe filtarate by adding hydrochloric acid and evaporating to dryness. When he washed the residue with alcohol, everything dissolved except a beautiful dark red powder, which proved to be a double chloride of sodium and a new metal, which because of the rose color of its salts, Dr. Wollaston named 'Rhodium'. He found that the sodium rhodium chloride could be easely reduced by heating it in a current of hydrogen, and that after the sodium chloride had been washed out, the rhodium remained as a metallic powder. he also succeeded in obtaining a rhodium button.""(Weeks: Discovery of the Elements. p. 104-05.)‎