Extramural lecturing thumb|right|Poster announcing the Joseph Lister lecturers at High School Yards On 7 November 1855, Lister gave his first extramural lecture on the "Principles and Practice of Surgery", in a lecture theatre at 4 High School Yards known as Old Jerusalem, directly located across from the infirmary. His first lecture was read from 21 pages of foolscap folio. Lister's first lectures were based on notes, either read or spoken, but over time he used notes less and less, becoming extempore in his speech, slowly and deliberately forming his argument as he went along. With this deliberate way of speaking, he managed to overcome a slight, occasional stammer which in his early days had been more pronounced.
extramural lecturing thumb|right|poster announcing the joseph lister lecturers at high school yards on 7 november 1855 lister gave his first extramural lecture on the "principles and practice of surgery" in a lecture theatre at 4 high school yards known as old jerusalem directly located across from the infirmary his first lecture was read from 21 pages of foolscap folio lister's first lectures were based on notes either read or spoken but over time he used notes less and less becoming extempore in his speech slowly and deliberately forming his argument as he went along with this deliberate way of speaking he managed to overcome a slight occasional stammer which in his early days had been more pronounced