Magnesia

Metals minerals and metallic preparations · A Chymical Dictionary

At a Glance

The word. One name with a common mineral use and a distinct artificial preparation.

In the book. Marcasita gives the broader account of unripe metallic matter.

A place to read. The historical definition below, 1650 dictionary, unnumbered definition page 31; facsimile PDF page 359.

Historical Definition

Magnesia is commonly used for a marcasite; artificial magnesia is tin melted with quicksilver, the two being mixed into a brittle, white mass.

Meaning

The definition expressly separates what is commonly meant from what is made artificially. In the first use Magnesia leads to marcasite. In the second, the compiler describes the union of tin and quicksilver, with brittleness and whiteness as properties of the resulting mass. Those two accounts should not be blended into a single unspecified mineral.

The product’s name therefore depends partly on the context in which it occurs. A passage about a mine may require a different reading from a passage describing a prepared mass, even though both use Magnesia.

Use in the Book

Marcasita gives the broader account of unripe metallic matter. Iupiter names tin and Luna compacta names quicksilver. These equivalents provide a route through alternative names for the materials mentioned in the artificial branch of the definition.

Places to Read

Marcasita. A varied category of metallic matter understood as unripe.

Iupiter. The planetary name Jupiter denotes tin here.

Luna compacta. A lunar compound assigned to quicksilver.

In This Edition

The modernised wording keeps the two uses separate and does not substitute the modern material suggested by a familiar-looking name.

Historical source: 1650 dictionary, unnumbered definition page 31; facsimile PDF page 359 — Facsimile

Sources. A Chymical Dictionary 1650, 1650 dictionary, facsimile PDF page 359, Magnesia

See also. Marcasita; Iupiter; Luna compacta