A change of method, then, has given us General and Regional Anatomy.  These, too, have been worked so thoroughly, that, if not exhausted, they have at least become to a great extent fixed and positive branches of knowledge.  But the first of them, General Anatomy, would never, have reached this positive condition but for the introduction of that, instrument which I have mentioned as the second great aid to modern progress.

This instrument is the achromatic microscope.  For the history of the successive steps by which it became the effective scientific implement we now possess, I must refer you to the work of Mr. Quekett, to an excellent article in the “Penny Cyclopaedia,” or to that of Sir David Brewster in the “Encyclopaedia Britannica.”  It is a most interesting piece of scientific history, which shows how the problem which Biot in 1821 pronounced insolvable was in the course of a few years practically solved, with a success equal to that which Dollond had long before obtained with the telescope.  It is enough for our purpose that we are now in possession of an instrument freed from all confusions and illusions, which magnifies a thousand diameters,—­a million times in surface,—­without serious distortion or discoloration of its object.

A quarter of a century ago, or a little more, an instructor would not have hesitated to put John Bell’s “Anatomy” and Bostock’s “Physiology” into a student’s hands, as good authority on their respective subjects.  Let us not be unjust to either of these authors.  John Bell is the liveliest medical writer that I can remember who has written since the days of delightful old Ambroise Pare.  His picturesque descriptions and bold figures are as good now as they ever were, and his book can never become obsolete.  But listen to what John Bell says of the microscope: 

“Philosophers of the last age had been at infinite pains to find the ultimate fibre of muscles, thinking to discover its properties in its form; but they saw just in proportion to the glasses which they used, or to their practice and skill in that art, which is now almost forsaken.”

Dr. Bostock’s work, neglected as it is, is one which I value very highly as a really learned compilation, full of original references.  But Dr. Bostock says:  “Much as the naturalist has been indebted to the microscope, by bringing into view many beings of which he could not otherwise have ascertained the existence, the physiologist has not yet derived any great benefit from the instrument.”

These are only specimens of the manner in which the microscope and its results were generally regarded by the generation just preceding our own.