Franz Ritter von Soxhlet is credited with inventing an extraction apparatus in 1879 that now bears his name. Soxhlet was a German agricultural chemist of Belgian “extraction” from Brünn (now Brno in the Czech Republic) working in the area of milk characterization at the Vienna Agricultural Institute.

Soxhlet spent most of his career in the analysis of milk and its constituents. In an attempt to isolate the fatty constituents from milk, he (and students) had been attempting to use an extraction apparatus developed by another Brno chemist, Professor Zulkowski. Soxhlet developed a technique whereby milk was absorbed into a quantity of calcium sulfate powder and then submitted to extraction by ether. The Zulkowski apparatus proved problematic, however. Solids were able to find their way over the extraction tube and into the solvent reservoir. Modifications of the design also suffered from inefficiencies that apparently required extended operation.

A student of Soxhlet, a Hungarian fellow by the name of Mr. Szombathy, contrived a solution to the problem. Szombathy is credited with coming up with the clever siphon feature that so distinguishes what we now call the Soxhlet extractor.

It has been lamented that the efficiencies gained by the siphon discharge design have been partially lost due to the entertainment effect. Generations of chemists have dropped what they are doing to stand and watch the collection thimble fill and subsequently discharge dramatically through the siphon. You have to take your fun where you can find it.

Well done, Szombathy!

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