水銀

1. Origins, structure, and basic meaning

• Structure: 水銀 (すいぎん) is the substance noun mercury.
• Basic usage: 水銀について学ぶ makes mercury the study topic; 水銀を含む器具 identifies equipment containing it.

2. Common pitfalls and similar expressions

• Substance and containment
  • について marks the topic, while を含む marks the contained material; the equipment itself is not mercury.