Arsenic

Arsenic has a reputation as the 'king of poisons' and the 'poison of kings.' Throughout history, arsenic was a favorite murder weapon because it is tasteless, odorless, and its symptoms mimicked natural illness. It has been known since ancient times, though Albertus Magnus is often credited with isolating it around 1250. Napoleon Bonaparte may have been slowly poisoned by arsenic in the green-dyed wallpaper of his exile home.

Despite its dark history, arsenic has useful applications. It is used in semiconductors (gallium arsenide), wood preservatives, and certain pesticides. Tiny amounts of arsenic are actually found naturally in food and water. Some bacteria can even use arsenic for energy instead of oxygen, discovered in California's Mono Lake.

Arsenic's symbol 'As' is one of the most useful two-letter elements in Spellement. It directly matches the common English word 'as,' and it appears at the start of words like 'ask' and 'ash.' This makes arsenic a natural and frequent building block in element-based word spelling.