Balneum roris

Operations instruments and practitioners · A Chymical Dictionary

At a Glance

The word. A vapour-heated arrangement distinguished from the water bath.

A place to read. The historical definition below, 1650 dictionary, unnumbered definition page 10; facsimile PDF page 338.

Historical Definition

Balneum roris is a furnace in which the distillation vessels are placed over the water’s vapour alone, so that the vapour does not touch the body. It is also called a vaporous furnace.

Meaning

The definition’s spatial relations matter: the vessels are over vapour, and the vapour is said not to touch the body. “Body” here belongs to the material being worked rather than necessarily to the outside of the apparatus. The historical sentence is compressed, so a diagram or a more detailed passage would be needed before reconstructing every part of the arrangement.

Compare Balneum Mariæ, where the chemical vessels are placed in warm water. The distinction concerns how warmth reaches the vessel and its contents. Neither name should be read simply as a synonym for any bath or furnace. The alternative name “vaporous furnace” is useful in following different descriptions of the same stated arrangement.

Places to Read

Balneum Mariæ. A water bath used to warm vessels for several kinds of work.

Cucurbita. A gourd-shaped vessel.

Historical source: 1650 dictionary, unnumbered definition page 10; facsimile PDF page 338 — Facsimile

Sources. A Chymicall Dictionary (1650), s.v. Balneum roris ; compare Balneum Mariæ, Cucurbita

See also. Balneum Mariæ; Cucurbita