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Re: Chemistry in Archaeology

Subject: Re: Chemistry in Archaeology
From: "Michael Kuettner"
Date: Sat, 10 Dec 2005 23:31:13 +0100
Newsgroups: sci.archaeology
<bernard_connor@xxxxxxxxxxx> schrieb im Newsbeitrag 
news:1134210900.938452.176620@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> The invention of fire was probably the point where chemistry began to
> have a decisive role in archaeological studies.

Could you rephrase that ?

> The immediate advntages
> were in warmth and cooking. Its significance in history is most easily
> seen in the evolution of metallurgy and chemical eaponry.
>
Some thousands of years between them; but it would be niggardly
to point that out ...
Watching nature to know that treating wooden stakes with the nice
ripe juices of old corpses doesn't make it chemistry ...

> The most readily available metals to early mankind were gold, silver
> and coper as they are relatively or totally inert to oxidation.

Gold and silver also had the advantage of being totally useless for
tools. Too soft ...
And if silver were that inert to oxidation, why does one have to clean
one's cutlery made of silver ?

> Hence
> they can be extracted directly in the metallic state.  Samples of cast
> copper go back at lest to ca 4,000 B C ( Egypt and Babylonia). Tin is
> also readily extracted from its ores and when alloyed with copper it is
> known as bronze. Hence the beginning of the Bronze Age.
>
<Sarcasm on>
Interesting. I didn't know that !
<sarcasm off>
Your point ?

> Silver was known in predynastic Egypt (ca 4,000 B C.) and is not
> oxidised in the cold or when heated,

And how does one call the patina on silver ?
Non-oxidation ?

> similarly with gold. Both found
> favour with the ancients as ornaments rather than as weapons because of
> the greater efficiency of copper and bronze.
>
Oh, a chemists view of hardness !
It was easier to take gold with a sword of copper than the other way round.
Just as a hint.

> The extaction of iron represented a major step forward as it requires
> very high temperatures to eextact it from its oxides. The most common
> oxide used in ancient times was magnetite, which has its own
> significance in history as a component in the compass. But that was
> much later.
>
What are "ancient times" ?
You really should try to define your vocabulary at least a little bit.

> Alumina can now be reduced  to aluminium at very high temperatures, but
> it took the development of electrolysis by Davy and later Faraday to
> extract it by electrolyis. Without this element it is unlikely that
> aircraft and space vessels would exist.
>
And that has to do with archaeology exactly what ?

> The use of fire made the development of alchemy possible. Aristotle
> believed that matter in its simplest form consisted of four elements:
> Fire; earth; air & water .
>
It was LITTLE bit more complicate than that, but OK.
Again, what is your point ?

> Robert Boyle published his book " The Sceptical Chymist" in the early
> 17 Century and destroyed the basis of alchemy by listing genuine
> elements for the first time. Later Mendelelev classified these in his
> Periodic Table.
>
And that was the birth of chemistry, fine.
But that's history, not archaeology.

> There is another less well known classification of the metals in the
> Ellingham Diagrams. Ellingham's work is largley forgotten There are
> only 25 references to the diagrams in the Google Search Box and all of
> these are from metallurgical or physical chemistry journals. In graphic
> form they show how the properties of the metallic oxides can be used to
> illustrate the history of metal extaction based on the thermodynamic
> properties of their ores.
>
Now, THAT would be an interesting point if you could expand on how that
classification might have had any effects in antique metal-working.

> Ironically, the transmutation of base metals into gold is now
> achievable through nuclear fission, but it too expensive and hazardous.
>
We know that, too. Your point ?

If you want to be taken seriously around here, try to make a point instead
of just babbling.

Cheers,

Michael Kuettner

PS :
IE Johansson is a stupid  , btw. And Deppo Renfors is a moron.
If you want to keep that company, just say so. It's early killfiling,
then.










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