Who chaired Fleming's 1929 Medical Research Club talk on penicillin?

Henry Dale chaired the Medical Research Club meeting at which Fleming discussed his 1928 penicillin discovery in 1929.

Fleming presented the work on 13 February 1929 in a paper titled “A medium for the isolation of Pfeiffer's bacillus.” The talk described the antibacterial action of material produced by Penicillium, but it attracted little immediate attention. Dale, then director of the National Institute for Medical Research, chaired the meeting and later recalled that he had not recognized the discovery's full importance at the time.

This episode is often misunderstood because the discovery was not instantly celebrated. Fleming published his findings later in 1929, but penicillin was difficult to purify and produce in useful quantities. Harold Raistrick tried to investigate its chemistry, while Howard Florey and Ernst Chain's Oxford team eventually developed methods that made clinical use possible. Dale himself later won the 1936 Nobel Prize for work on chemical transmission of nerve impulses.