|
|
|
|
|
51:9 ·
In Diderot's Encyclopedia this sign is said to mean blanc d'Espagne, a natural calcium carbonate, for the chemists of eighteenth century France. |
|
|
|
|
|
|
|
51:9 ·
In Diderot's Encyclopedia this sign is said to mean blanc d'Espagne, a natural calcium carbonate, for the chemists of eighteenth century France. |
