thalline (thalin)

[ thamnium first supposed to contain tellurium, but after-. ward proved, by the aid of the spectroscope, to be new. Thallium as prepared artificially has a bluish white tint and the luster of lead. It is malleable, and so soft that it can be scratched with the finger-nail. Its specific gravity is 11.8. Thallium is somewhat widely distributed, but never occurs in large quantities. The rare mineral called crookesite, found in Sweden, is an alloy of thallium, selenium, and copper, with a little silver. Thallium seems to be present in both iron and copper pyrites from various localities, and it is from the fluedust from sulphuric-acid works in which pyrites is burned that the metal is chiefly obtained. Thallium is chemically cla ed with the metals of the lead group, but its reactions are in certain respects very peculiar and exceptional. It has been employed in the manufacture of gla , and is said to furnish a gla of extraordinary brilliancy and high refractive power.