In connection with his teaching Graham developed specially the botanical excursion for the study of Field Botany, making it an integral part of his courses, and in furtherance of its aims travelling far through Scotland--a business of a much more arduous nature in days when railways and motors had not annihilated distance and provided all the comforts of civilisation within easy reach of every district. Graham had intended to publish a _Flora_ of Scotland as the result of his practical study of its plants, but it was uncompleted at the time of his death in 1845 after an illness of some duration during which (Sir) Joseph Dalton Hooker acted as _locum tenens_. Another new method in his teaching was that of encouraging students to write essays upon subjects either practical or theoretical. In this he stimulated investigation. Students in these days had more time than they have now to devote to such things, and of their efforts some were sound pieces of research--the _Botanical Geography_ of Hewitt C. Watson first took form in one of these essays. John Hutton Balfour[135], who succeeded Graham, was born in Edinburgh 15th September, 1808. The eldest son of Andrew Balfour, surgeon in the Army, who afterwards settled in Edinburgh as printer and publisher, in which business his enterprise was adequate to the venture of the _Edinburgh Encyclopaedia_ under the editorship of (Sir) David Brewster. Andrew Balfour was a grim old presbyterian of the stuff covenanters were made, and in the strict home environment which he created young Balfour early came into touch with theological dogma. The echo of these early impressions remained with him throughout life. Educated at the High School of Edinburgh where he laid the foundation of sound classical scholarship--always his unobtrusive distinction--Balfour entered the curriculum for the Arts degree at the University. Before completing this he migrated to St Andrews in order to be under the influence of Professor Thomas Chalmers--the famous Divine, afterwards leader in the disruption that founded the Free Church of Scotland--in conformity with the desire of his father that he should become a minister in the Church of Scotland. But Divinity did not claim him and he returned to Edinburgh to begin the study of Medicine--a decision in face of family pressure which is tribute to the strength of purpose which characterised him and found expression frequently in after life.