Specifically, it's Lead Acetate vs a lump of metal lead.
"Lead acetate, also known as sugar of lead, is a salt that (ironically) has a sweet flavor—a fairly unusual quality in poisons, which are more likely to taste bitter, signaling to the taster that they are unsafe for consumption. The ancient Romans used the compound—which they called sapa—to sweeten wine"
"Lead acetate, also known as sugar of lead, is a salt that (ironically) has a sweet flavor—a fairly unusual quality in poisons, which are more likely to taste bitter, signaling to the taster that they are unsafe for consumption. The ancient Romans used the compound—which they called sapa—to sweeten wine"
https://www.smithsonianmag.com/arts-culture/sugar-of-lead-a-...