thallium

thallium is defined in Webster's Unabridged Dictionary (1913) with 1 sense. The full text of each entry is reproduced verbatim below.

Definitions

  1. 1.A rare metallic element of the aluminium group found in some minerals, as certain pyrites, and also in the lead-chamber deposit in the manufacture of sulphuric acid. It is isolated as a heavy, soft, bluish white metal, easily oxidized in moist air, but preserved by keeping under water. Symbol Tl. Atomic weight 203.7.

Source: Webster's Unabridged Dictionary, 1913 edition (public domain, via GCIDE / Project Gutenberg).

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