From the book
A Chymical Dictionary
Gerhard Dorn and John French · Diotimos Editions · 2026
Browse this book’s lexicon →Orientation
At a Glance
- The wordA calx classified by resistance to burning.
- A place to readThe historical definition below, 1650 dictionary, unnumbered definition page 13; facsimile PDF page 341.
Historical definition
Calx permanens, or fixa, is an incombustible matter.
Meaning
The definition identifies a property rather than naming the starting substance. Permanens and fixa are offered as alternative qualifiers, and incombustibility supplies their explanation here. The entry does not say that every fixed matter or every calx elsewhere is identical with it.
Fixatio provides a related operation word. Comparing the two can help a reader distinguish a material described as fixed from the process of making something fixed. The historical claim of incombustibility should be interpreted through the particular passage’s account, not turned into an unlimited statement about every possible condition.
Places to read
- Calx permanensRead the complete historical definition and its commentary.
- FixatioAn operation defined through resistance to loss or flight in fire.
- Calx lignorumA direct identification of a calx as ash from wood.
Source note
Historical source. 1650 dictionary, unnumbered definition page 13; facsimile PDF page 341 — Facsimile
Sources. A Chymicall Dictionary (1650), s.v. Calx permanens ; compare Fixatio, Calx lignorum