Fern, glasswort and soda

Meaning

Fern, fougiere, and salicot ou soulde, rendered “glasswort or soda,” are examples of things from which salt is obtained for glassmaking. Their argumentative work is to raise a difficulty: if salt makes glass, might salt itself explain the hardness of bones, husks and shells? Nuysement answers by contrasting his asserted solubility of salts with the moisture-resistance of vitrified bodies. These vernacular examples therefore belong to an objection and reply about hardness, not an ingredient list. The alternative ou should remain visible in the linked names, and “soda” here does not establish a single modern compound or extraction method.