> In following the oiling shells conversation,  I'm reminded that I have used
> glycerin on  my Paryphanta lignaria lusca to keep the periostracum from
> drying up and popping off of the shell . I have heard stories of the shell frac-
> turing into many small  pieces in an explosive manner. Glycerin was always
> recommended for protection.
>
> However, it renders the shell useless for scanning electron microscope work,
> so I've been told. How does it interfere ?  Is this true with all shells ? Would
> mineral oil work just as well for the paryphanta ?
>
> Glycerin is hygroscopic, absorbing moisture from the air. It dissolves into alcohol
> or water, but will not dissove into oil. It also has a very high boiling point. Glycerin
> is used in clear soaps, in lotions as an emollient, in lubricants for molds and for
> scientific specimen preservation. Who else uses it on shells ?
>
> Is glycerin better or worse  than oil for coating shells if they are not going to be
> used for research under the  microscope?
>
> Thank you.  Don't forget to turn your clocks  back on Saturday.
>
> Mathilde Duffy
> [log in to unmask]
> Watertown, MA  ( Boston suburb )