TO 



JOHN WILLIAM DKAPEB, M.D., LL.D, 



PROFESSOR OP CHEMISTRY AND PHYSIOLOGY IN IflB 



UNIVERSITY OF NEW YORK. 



DEAR SIR: 



IT seems peculiarly appropriate that this volume should be dedicated to 

 you. Knowing the eminent esteem in which you are held in the circles of 

 European science, I cannot doubt that the distinguished authors of the fol 

 lowing essays would cordially approve this connection of your name with 

 their introduction to the American public. 



There is, besides, a further reason for this in that large coincidence of 

 purpose which is manifest in their labors and your own. For while the per 

 vading design of the present collection is to widen the range of thought by 

 unfolding a broader philosophy of the energies of nature, your own compre 

 hensive course of research beginning with an extended series of experi 

 mental investigations in chemical physics and physiology, and rising to the 

 consideration of that splendid problem, the bearing of science upon the His 

 tory of the Intellectual Development of Europe has powerfully contributed 

 to the same noble end ; that of elevating the aim and enlarging the scope of 

 scientific inquiry. 



I gladly avail myself of this occasion to say how greatly I am indebted 

 to your writings, in which accurate and profound instruction is so often and 

 happily blended with the charms of poetic eloquence. That you may live 

 long to enjoy your well-won honors, and to contribute still further to the 

 triumphant advance of scientific truth, is the heartfelt wish of 



Yours truly, 



E. L. y. 



