[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Water in Meteorites - Part 2 of 2

Ron wrote:

> I'm not sure when the first water samples was extracted from a
> meteorite, but it was probably from a carbonaceous chondrite.

Well, the excerpt from Cohen shows that water had already been
extracted from meteorites more than 100 years ago. It is interesting
to note that Cohen and his fellow scientists still believed in the
terrestrial provenance of these water traces:

COHEN E. (1894) Meteoritenkunde, Heft 1, pp. 220-224: Wasser

"Die meisten Meteoritenforscher - eine Ausnahme machen Daubrée, Mohr
(12. 260) und Winkler - scheinen darin einig zu sein, dass Wasser als
ursprünglicher Bestandtheil von Meteoriten nicht vorkommt, sondern erst
innerhalb unserer Atmosphäre aufgenommen, vielleicht auch gelegentlich
aus seinen Elementen gebildet worden ist. Damit stimmt auch überein,
dass man Wasser in irgend erheblicher Menge vorzugsweise in solchen
Steinen gefanden hat, welche in Folge ihrer lockeren Beschaffenheit
besonders günstige Bedingungen für die Aufnahme bieten, und dass sich an
der Zusammensetzung der Meteoriten kein Mineral betheiligt, welches
Constitutions- oder Hydratwasser enthält.
Pisani beobachtete z. B., dass, Pulver des kohligen Meteoriten von
Orgueil, welches durch Trocknen bei 100° 9.15 % Wasser verloren hatte,
7% während weniger Stunden wieder aufnahm. Faraday fand 1839 in Cold
Bokkeveld, also bald nach dem Fall (October 1838) nur 6 ½ % Wasser,
Wöhler 1860 10 ½; ... "

Partial translation by me:

Most meteoriticists seem to agree - with the exception of  Daubrée, Mohr
and Winkler - that water does not exist as an indigenous constituent of
meteorites, but that it was taken up only within our (terrestrial)
atmosphere or that it was occasionally formed from its elements. This is
in agreement with the existence of small amounts of water preferably in
those stones that, due to their friable nature, offer very fortuitous /
favorable conditions for the absorption of water, ...

Pisani*, for example, had observed that powder of the Orgueil
carbonaceous chondrite which had lost 9.15 % water during drying at
100°C, had again taken up 7 % water within a few hours ...

* PISANI F. (1864) Etude chimique et analyse de l'aérolithe d'Orgueil
(C.R. 1864, LIX 133).


Best regards,

Bernd

----------
Archives located at:
http://www.meteoritecentral.com/list_best.html

For help, FAQ's and sub. info. visit:
http://www.meteoritecentral.com/mailing_list.html
----------