Debray (Comptes rendus, 1874, 78, p. 1502).
4 (Deville and Debray), and is only fusible with great difficulty.
Debray and A.
Berzelius was an early worker in this field; he was succeeded by Bunsen, and Deville and Debray, who worked out the separation of rhodium; and at a later date by P. T.
Debray (1827-1888) he worked at the platinum metals, his object being on the one hand to prepare them pure, and on the other to find a suitable metal for the standard metre for the International Metric Commission then sitting at Paris.
Debray in the case of rhodium, iridium and ruthenium, which evolve heat when they are dissolved in zinc. When the solution of the rhodium-zinc alloy is treated with hydrochloric acid, a residue is left which undergoes a change with explosive violence if it be heated in vacuo to 400°.
Its specific gravity is 21.3-22.48 (Deville and Debray) and its specific heat is 0.03113 (Regnault).
Debray (ibid., 1879, 88, p. 1341), who found that at about 150o C. a condition of equilibrium is reached.
Debray prepared it, in a compact state, by reducing the volatilized chloride with melted sodium, in an atmosphere of hydrogen.
Debray, Comptes rendus, 1861, 52, p. 985).
A crystalline form was obtained by Debray as olive-green prisms by igniting a mixture of sodium tungstate and carbonate in a current of hydrochloric acid gas, and by Nordenskjold by heating hydrated tungstic acid with borax.