From: owner-scribes@castle.org (scribes digest) To: scribes-digest@castle.org Subject: scribes digest V5 #78 Reply-To: Sender: owner-scribes@castle.org Errors-To: owner-scribes@castle.org Precedence: bulk scribes digest Tuesday, March 13 2001 Volume 05 : Number 078 ======================================================================== 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. [scribes]: Mistress Alicia [scribes]: Sulfur interactions... ---------------------------------------------------------------------- Date: Tue, 13 Mar 2001 14:57:37 -0600 From: "Amy L. Hornburg Heilveil" Subject: [scribes]: Mistress Alicia Would Mistress Alicia (mka Della H.) please contact me privately? Thank you, Despina - ---------- - ---------- Think for yourself and let others enjoy the privilege of doing so too. - --Voltaire =================================================================== 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. ------------------------------ Date: Tue, 13 Mar 2001 15:46:00 -0800 (PST) From: Bryan Bell Subject: [scribes]: Sulfur interactions... >RanthulfR wrote: >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. That is quite true, because of the comment below from Therasia... >Therasia wrote: >The sulfur can come from >three different sources: from other adjacent pigments containing sulfur... >from the sulfur inherent in glaire or egg >tempura as aglutenants, or from SO2, a major constituent of air >pollution. Essentially what happens is that there is still air inside the glassed frame. So to be brief, an equilibrium occurs where some of the sulfur in a pigment interacts with some of the oxygen and carbon dioxide to form SO2, which disperses in the air inside the frame. Now, this occurs in a much smaller scale than if the piece were directly exposed in an area, say, near heavy industry (especially around a big city or anywhere where coal is used). But, over time, the pigments will interact with the amounts of SO2, and take on their sulfide forms. >Theresia wrote: >the sulfur can react to form PbS, which is the black mineral galena. Lead sulfide (PbS) is an actual compound (in addition to being what the mineral galena is primarily composed of--any mineral also having traces of other elements within their lattice structures). I think it would be better science to think of the PbS as a coating or powder, so to speak, much like the patina when copper oxidizes, or the oxidized (dull) side of aluminum foil. A chemical reaction is taking place with both oxidation and the creation of sulfides. So we're not getting galena crystals actually growing, but rather lead sulfide is being formed from the conversion of the lead oxide (PbO). And the fixers hold the powder in place just like any other pigment. >RanthulfR wrote: >I was also unaware of traces of sulphur in egg white, which is what >glair is made from. Oh yes, who hasn't smelled a rotten egg? Those are sulfides, predominately H2S, or hydrogen sulfide, that are causing the characteristic odor. Which, as an aside, can be quite deadly if it builds up in a crawl space as a result of a ruptured septic line.... The sulfides are in all parts of the egg, just in lesser quantities in the white. Garlic also gets its characteristic odor from sulfide links within the herb. That's why some people can sometimes get a "sour" or garlicky odor from perspiring after eating a meal with lots of garlic--the body excretes the compounds through the sweat glands! (I have been known to smell like garlic for two days after eating an Italian meal loaded with garlic--much to my chagrin! Sorry, that's probably too much sharing for one e-mail...) >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. That is quite interesting--I'd like to find out more about that chemistry. I won't bore you with my thoughts on why, which have to do with icky, tedious stuff (well, fun for me) like electron structures and coordination chemistry... Your resident chemist at large, Bryan (mundane) =================================================================== 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 #78 ****************************