This volume is the first of a series designed by the Author with the purpose of placing in the hands of the public, in more serviceable form, those portions of his earlier works which he thinks deserving of a permanent place in the system of his general teaching. They were at first intended to be accompanied by photographic reductions of the principal plates in the larger volumes; but this design has been modified by the Author's increasing desire to gather his past and present writings into a consistent body, illustrated by one series of plates, purchaseable in separate parts, and numbered consecutively. The note at page 147 in this volume, (lying by during my illness,) referred to the smaller photographs at that time in preparation: but the extension of the plan will render all directions to the binder unnecessary, except such as the possessor of the book may himself issue. Of other prefatory matter, once intended,—apologetic mostly,—the reader shall be spared the cumber: and a clear prospectus issued by the publisher of the new series of plates, as soon as they are in a state of forwardness.

The second volume of this edition will contain the most useful matter out of the third volume of the old one, closed by its topical index, abridged and corrected.