This is a routine acid-base extraction of an alkaloid which in this case is the penicillin byproduct from the mold produced on the agar in the first scenes. Diethyl ether is then poured in to extract the penicillin into it and then filtered under vacuum filtration with a Büchner funnel. Acidified water is then added which separates into two layers also known as phases. This then forms the acid salt of penicillin, most notably the hydrochloride or sulfate. The diethyl ether now only contains the impurities left behind as the penicillin is dissolved in the water layer also known as the aqueous phase. The diethyl ether dirty brown liquid is then being disposed of in the bathtub looking apparatus. Clean ether is then added to the acidified water phase containing the penicillin salt and then the PH is made alkaline with and what I’m assuming is sodium hydroxide, sodium carbonate, or a similar base. The mixture is then agitated to dissolve the penicillin free base in the ether which is then filtered off again, centrifuged to speed up the separation process, and this leaves the reddish/brown liquid phase with the crude amoxicillin base in it. [Description provided by a subscriber to the library's youtube channel https://www.youtube.com/watch?v=NIrDi9BG2Es&lc=z22dtjcilyvrcxhxl04t1aokgwiasvjkqbhxpzi10mh5bk0h00410 ]. The man performing the extraction is possibly Howard Florey, based on a comparison with pictures of Florey at the Oxford History of Science Museum website: http://www.penicillinstory.org/gallery-layouts/gallery_step_6.html . The setting may be the penicillin extraction plants in the Dunn School of Pathology, University of Oxford, based on comparisons with pictures of the equipment at https://www.mhs.ox.ac.uk/wp-content/themes/mhs-2017-responsive/imu-media.php?irn=54720 [Detail provided by a researcher via Collections enquiries, April 2020].