I found this glassware in a phytochemistry lab abandoned in the 1990ies. The piece itself was shelved in the storage room, thus probably already obsolete back then. The device, entirely glass, is a compact sequence of six bulbs (relative sizes: L, S, S, S, M, XS), 155 mm wide and 105 mm high. As a layman I'd guess it was used to separate, maybe distill liquid fractions.

Thank you in advance for identification or ideas.

Geissler potash bulbs

Edit: flipped picture horizontally and marked inlet.

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    $\begingroup$ In the good old days Amoco R&D had its own glass shop and people would bring in their own designs for unique equipment. So there can be some pretty unusual stuff. $\endgroup$ Nov 30, 2022 at 21:27

1 Answer 1


This is Geissler potash bulbs (German “Geißler’schen Kaliapparat”/“Kaliapparat nach Geißler”) designed and produced by Heinrich Geissler in 1860s and primarily used in the second half of 19th century to quantify carbon dioxide content in the air or among the products of combustion analysis of organic matter.

The apparatus has several advantages over the original version of potash bulb devised by Liebig in 1831 (which is depicted on the ACS logo since 1908), such as improved stability (convenient for placement on a table), but is was also prone to clogging by building up potassium carbonate and was more expensive and complex to build. Several versions of the apparatus existed and they still were sold in 1910s (items 6011 to 6014, image courtesy of Science History Institute — Illustrated Catalogue of Scientific Apparatus, Chemical Glassware, and Laboratory Supplies, ca. 1910, p. 201):

Potash bulbs depicted in Illustrated Catalogue of Scientific Apparatus, Chemical Glassware, and Laboratory Supplies

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    $\begingroup$ Some times, I still wonder how these vintage people come-up with such creative ideas. $\endgroup$ Nov 29, 2022 at 23:41
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    $\begingroup$ Slightly off-topic, but can you explain why the numbering of the figures is out of the expected order? $\endgroup$ Nov 30, 2022 at 10:42
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    $\begingroup$ @LokiRagnarok - I would presume poor communication between the artist and the person numbering the items. $\endgroup$
    – Jon Custer
    Nov 30, 2022 at 13:31
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    $\begingroup$ @MathewMahindaratne They didn't have TV. $\endgroup$
    – user8035
    Nov 30, 2022 at 20:30
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    $\begingroup$ Could something like I_O's piece be (safely) repurposed into a Geissler tube lamp? Very cool find and amazing it's survived! $\endgroup$
    – GB540
    Nov 30, 2022 at 22:55

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