f modest men, would in all probability be the pupils, and the trembling
candidate the instructor. It would appear from this that microscopic
embryology has been with Dr. Thomson a favourite field of study and
research from his youth upwards. The inaugural dissertation was,
however, but a brief antepast of something more exhaustive to follow. In
the same year in which he took his degree, we find him coming before the
scientific world through the medium of the _Edinburgh New Philosophical
Journal_, with a series of elaborate papers, entitled "The Development
of the Vascular System in the Foetus in Vertebrated Animals," a
contribution which is admitted on all hands, we believe, to be perhaps
the highest and safest authority on its intricate and recondite
subject-matter that as yet exists. We are not aware whether Dr. Thomson
entered on the study of medicine with any view of going into the arduous
and often unremunerative toils of private practice. If so, the idea must
have been soon abandoned, as we have him, in 1832, becoming a Fellow of
the Royal College of Surgeons, Edinburgh, and thereafter betaking
himself, as an extra academical lecturer, to the teaching of the
Institutes of Medicine. The labours of the class-room would seem,
however, not to have in any way overtasked his energies, as we find that
in the same year he was again before the public as an author. The
publication which saw the light on this occasion was an "Essay on the
Formation of New Blood Vessels in Health and Disease," a subject at once
full of practical interest to both physician and surgeon, and a most
natural supplement to the _magnum opus_ on the development of the
vascular system. The same period, too, occasionally found Dr. Thomson not
unwilling to appear before lay audiences with lucid, instructive
expositions of the structure and functions of our wonderfully-made
frame--a fact, we daresay, of which many middle-aged citizens of
Edinburgh will, even still, retain a pleasing recollection. As regards
his professional courses on physiology, these he continued to deliver up
to 1836, when the removal of his colleague and intimate friend, Dr.
Sharpey, from Edinburgh to the Chair of Anatomy and Physiology of the
London University College, induced him to open classes for extra-mural
students of anatomy, at that time a somewhat numerous body in the
northern metropolis. As prelections and demonstrations on this
fundamental important branch of medical study