Sounds like  . . .your looking for wax.
Unless, its a resin. If you meant water-based, than agar at 4 or more % may do.
Cheers
Jim Darley
ProSciTech                 Microscopy PLUS
PO Box 111, Thuringowa  QLD  4817  Australia
Ph +61 7 4774 0370  Fax:+61 7 4789 2313  service@proscitech.com
Great microscopy catalogue, 500 Links, MSDS, User Notes
ABN: 99 724 136 560                      www.proscitech.com

On Saturday, July 22, 2000 3:07 AM, Jerry Chi-Yuan Hu 
[SMTP:ragnarok@ruf.rice.edu] wrote:
>
> Hello Everyone,
>
> I am looking for an embedding medium that is not toxic and hardens to an
> appreciable stiffness above 0oC.  Someone suggested OCT compound and
> gelatin, but he has only used it at -20oC, and he doesn't know how hard it
> can get above zero.  Any help or suggestions will be greatly appreciated.
>
> Jerry Hu
>