Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by composition]
6. inorganic material
7. [sodium and sodium compounds]
8. sodium compounds
9. sodium carbonate

Anotations

Scope note:

Hydrous sodium carbonate found in nature as evaporative residues. Used widely as a silica source in early glass manufacture; in ancient Egypt used as well as a bleach for linen, a preservative in mummification, and as an ingredient of incense.