Bookshelp header image for page World Wide Words logo

Cohobation

Pronounced /ˈkəʊhəʊbeɪʃən/Help with pronunciation

Many alchemists throughout history have held the curious belief that for a process to be successful it must be repeated many times. So it was common for substances not only to be distilled, but for the products of distillation to be returned to their residue and distilled again, perhaps several hundred times. This process of alchemical redistillation was called cohobation.

It was so common a technique that a special piece of apparatus was designed to make the whole process automatic, a flask with return tubes from the neck for the vapour to condense and pass back into the base of the vessel. It was called a blind alembic or a pelican. The latter name derives from the medieval heraldic image representing the ancient legend of the long-necked pelican wounding its breast to feed its young on its blood, the curve of the bird’s neck resembling one of the curved return tubes on the flask.

The origins of the word cohobation are mysterious, though the OED surmises that it may derive from an Arabic dialect root for “repeat”.

Share this page
Facebook Twitter StumbleUpon Google+ Email

Search World Wide Words

Support World Wide Words!

Donate via PayPal. Select your currency from the list and click Donate.


Buy from Amazon and get me a small commission at no cost to you. Select your preferred site and click Go!

OTHER WAYS TO HELP

Copyright © Michael Quinion, 1996–. All rights reserved.
Page created 11 Apr. 1998

Advice on copyright

The English language is forever changing. New words appear; old ones fall out of use or alter their meanings. World Wide Words tries to record at least a part of this shifting wordscape by featuring new words, word histories, words in the news, and the curiosities of native English speech.

World Wide Words is copyright © Michael Quinion, 1996–. All rights reserved.
This page URL: http://www.worldwidewords.org/weirdwords/ww-coh1.htm
Last modified: 11 April 1998.