RHODIUM is a white metal very difficult of fusion: its specific gravity is about 11: it is extremely hard. When pure the acids do not dissolve it (Brandt, 1001.)

Rhodium was discovered in 1803 by Dr. Wollaston, and has been long employed for the nibs of pens, which have been also made of ruby, mounted on shafts of spring gold; these kinds have had to endure for the last 7 or 8 years the rivalry of " Hawkins's everlasting Pen," of which latter, the author from many months' constant use can speak most favourably. " The everlasting pan," says the inventor," is made of gold tipped with a natural alloy, which is as much harder than rhodium as steel is harder than lead; will endure longer than the ruby; yields ink as freely as the quill, is as easily wiped, and if left unwiped is not corroded." See also Mec. Mag., 1840, p. 554. Mr. Hawkins employs the natural alloy of iridium and osmium, two scarce metals discovered by Tennant amongst the grains of platinum; the alloy is not malleable, and is so hard as to require to be worked with diamond powder. The metals rhodium, iridium, and osmium, are not otherwise employed in the arts than for pens; although steel has been alloyed with rhodium. See also the Quarterly Journal Royal lust., vol. ix.