Three microscopes used by William Osler Three microscopes used by William Osler in his early days as a student. The larger, middle one (A) belonged to Reverend William Arthur Johnson, Osler's teacher and mentor at Trinity College School. The small microscope on the left (B) was the property of Dr. A. Holford Walker, who practiced in Dundas and was the Osler family physician. Osler assisted Dr. Walker with his practice in the summer of 1869. Finally, Osler used the microscope on the right [C] after graduation (from what school is unclear).. [Description courtesy of McGill University.] Osler Library of the History of Medicine, McGill University. William Osler Photo Collection Photographic prints Archival Materials Still Image 1 pages nlm:nlmuid-101743406X6-img 101743406X6 http://resource.nlm.nih.gov/101743406X6 Profiles ID: GFBBBJ No linguistic content Profiles in Science