From: owner-scribes@castle.org (scribes digest) To: scribes-digest@castle.org Subject: scribes digest V5 #76 Reply-To: Sender: owner-scribes@castle.org Errors-To: owner-scribes@castle.org Precedence: bulk scribes digest Monday, March 12 2001 Volume 05 : Number 076 ======================================================================== To unsubscribe from this list, send email to with unsubscribe scribes-digets in the body of the message. Leave the subject line blank. Do not include any additional text. Re: [scribes]: My Day at the Newberry Library ---------------------------------------------------------------------- Date: Mon, 12 Mar 2001 10:51:01 -0500 From: Randy Asplund Subject: Re: [scribes]: My Day at the Newberry Library We might as well skip the speculation and jump right to the hands on experience: The way that the sulphur and lead interract is not just by mixing. If you put them in a picture apart from each other they will still interract under the glass of your frame. This happens when the gasses surrounding one spread over paint made with the other (I think the sulphur mixes with the atmosphere inside the frame and actually rises). This action will cause the lead color to revert to metallic looking lead. I wasn't aware of trace elements in tempura. I like the batter and will continue eating it. I was also unaware of traces of sulphur in egg white, which is what glair is made from. I could be in error there, since obviously the stuff grows together with the yolk. Nevertheless, my experience has been that orpiment can be painted with glair tempra. RanthulfR Catie Helm-Clark wrote: > > > > Yesterday, I visited the Newberry Library (their first annual Associates Day) > > and found out two rather interesting items. > > > > The first was (and I bet RanthulfR already knew this and told me about it, but > > it just didn't sink into my brain) that often white lead turned dark gray or > > even black on manuscript pages. So, even some stuff that many of us were saying > > was just tarnished silver leaf might very well have actually been white lead > > If I'm not mistaken, Mayer discusses this problem in _The Artist's > Handbook_ > (1977, Viking Press). The three volume collection _Artists' Pigments_ > (put > out jointly by the National Gallery in London and the Smithsonian) also > mentions > this in greater detail. The cause has to do with the chemistry of white > lead > and sulfur. White lead is a lead oxycarbonate, made by the slow > oxidation of > lead acetate. It's chemical structure is complex, and for an inorganic > pigment, > a bit wierd. If the lead white is exposed to sulfur, the sulfur can > react to > form PbS, which is the black mineral galena. The sulfur can come from > three > different sources: from other adjacent pigments containing sulfur > (orpiment, > realgar, vermillion, stibium...), from the sulfur inherent in glaire or > egg > tempura as aglutenants, or from SO2, a major constituent of air > pollution. > > Vermillion has the same problem, though its cause is unknown. > Vermillion is > the hexagonally symmetric form of HgS. For reasons still not clear, it > can > spontaneously rearrange itself into the cubic form of HgS which is > black. > > The Newberry is a cool place. I used to have a reader card there, and > went > and looked at the medieval manuscripts whenever I could (long ago in the > mists > of time when I was an undergrad at Northwestern) Unlike a lot of other > places > I've tried infiltrating to look at medieval stuff (eg, the Huntington > and Yale), > the Newberry is very friendly to non-professional, non-academic seekers > after > knowledge. It sounds like that haven't changed, which makes me happy. > > ttfn, Therasia > =================================================================== > To unsubscribe from this list, send email to > with a blank Subject: line and > unsubscribe scribes > in the body of the message. Do not include any additional text in > the body. - -- Randy Asplund (734) 663-0954 Science Fiction and Fantasy Illustration 2101 S. Circle Dr., Ann Arbor, MI. 48103 See a Universe of art ranging from Medieval Manuscripts to Star Trek and Magic: The Gathering at: http://www.provide.net/~randyaf =================================================================== To unsubscribe from this list, send email to with a blank Subject: line and unsubscribe scribes in the body of the message. Do not include any additional text in the body. ------------------------------ End of scribes digest V5 #76 ****************************