thallium
tha lee uhm
- n a soft grey malleable metallic element that resembles tin but discolors on exposure to air; it is highly toxic and is used in rodent and insect poisons; occurs in zinc blende and some iron ores
- There police found "enough thallium to keep a pharmacy in business for an entire month.
- Thallium is deadly poison itself, poisons every compound it goes into.
- Of all the poisons man has concocted to combat his insect and rodent enemies, thallium sulfate is one of the most potent.