The sulfur content of silk is such a small amount that it was missed
for many years by researchers - up to the mid-eighties.  This accounts
for inconsistencies in the literature.  It has been speculated that the
contribution of cystine to the the physical properties of the silk
fiber might be proportionately greater than its concentration (I can't
find the paper that discusses this, sorry).

David Walker
Talisman


On Jun 30, 2005, at 12:58 PM, Mary Ballard wrote:

> Silk fiber contains a negligible quantity of sulfur. However, it
> absorbs and
> retains sulfur in various forms. Heasoon Rhee and I wrote several
> papers on
> the tendency of silk to adsorb sodium lauryl sulfate (up to
> 2.73%owf).* In
> this instance the anionic surfactant acts as a 'shampoo and
> conditioner all
> in one' and gives the silk a slightly softer hand. Modern acid dyes
> for silk
> are going to have sulphonic acid substituents in order to make the dye
> soluble in water. I haven't heard of these components being a problem
> for
> silver but you could interface the silk with some sacrificial,
> absorbent
> like Pacifica cloth if you suspected a source of sulfur contamination.
> Mary
>
> *bibliographic references see http://www.bcin.ca/Interface/bcin.cgi
>