



Produced by Al Haines.




[Illustration: Cover art]




[Illustration: _Her child eyes were still upon him and seemed to ask for
something yet.  And, at this, he bent and kissed her gently, as he would
have kissed a child, and did not guess that, at the touch of his lips,
Sidonia's woman's soul was born_. (See page 196.)]




                          "IF YOUTH BUT KNEW!"


                                   BY

                         AGNES & EGERTON CASTLE

                               AUTHORS OF
                   "ROSE OF THE WORLD," "FRENCH NAN,"
                               ETC., ETC.



    "_Si jeunesse savait..._
    _Si vieillesse pouvait!_"
      (_Old French Song_)



                  WITH ILLUSTRATIONS BY LANCELOT SPEED



                                New York
                         THE MACMILLAN COMPANY
                                  1906

                         _All rights reserved_




                            COPYRIGHT, 1906,
                       BY THE MACMILLAN COMPANY.

            Set up and electrotyped.  Published April, 1906.



                             Norwood Press
                J. S. Cushing & Co.--Berwick & Smith Co.
                         Norwood, Mass., U.S.A.




                               *CONTENTS*


CHAPTER

      I. The Vagabond
     II. The Forest House
    III. Green Adventure
     IV. Parting of the Ways
      V. The Invitation of the Road
     VI. The Burg
    VII. Guests of Chance
   VIII. Roses of Trianon
     IX. Home-Coming
      X. The Burgrave's Welcome
     XI. Tangled Tales
    XII. The Burgrave's Farewell
   XIII. The *Oubliette*
    XIV. Love among the Ruins
     XV. *Furens quid Fem