[Avodah] Are there any chemists on Avodah?

[Micha Berger]

On Wed, Jan 05, 2011 at 02:37:52PM -0500, Hankman wrote:
: In the daf, 54a, the gemara brings a Tani Levi that describes the
: construction of the Misbeach. It was concrete-like in nature. It used
: forms much as we would today, aggregate of perfectly smooth stones
: (not to be felt when passing a fingernail over them) and some sort of
: matrix or "mortar" composed of some sort of mixture of sid, kunya and
: zefes, commonly translated as plaster or lime, lead, and pitch or
: bitumen. My question is about this "mortar" they used...

Mamcheh appears to mean "to disolve", according to Dr Jastrow. So I
don't a mixture, while accurate, is necessary the right mental image. I
think the lime is being used as an alkaline (wikipedia says it's caustic)
to reduce the lead. Bitumen and pitch, both tarry, are nore likely
to react with lead, but if we have a chemist rather than someone doing
web searches, it would help.

But back to the point, the lead was machah, and therefore not in a
shiny metal form when used for mortar. I'm figuring the verb holds
the answer, regardless of the chemical details.

:-)BBii!
-Micha