INTRODUCTION. 



GENERAL REMARKS ON THE INFLUENCE OF PHYSICAL AGENTS ON ORGANIZATION 



AND LIFE. 



CONTENTS : Object of the Work stated. Connexion of Organization with the Imponder- 

 able Principles. General Laws direct all Astronomical Occurrences and Physical 

 Events. Transitory Nature of all Combinations, and especially those which are Or- 

 ganized. Time is an Element of Life. Inorganic Changes are brought about by 

 Physical Laics, as also is the Extinction of Living Races. Influence of Climate on 

 the Distribution and Character of Animals and Plants. Relations between Animated 

 Forms and the Atmosphere. Influence of Currents in the Air and in the Sea. 

 Gradual Emancipation of the Higher Races from the Direct Action of External 

 Agents. 



1. THE rapid progress of organic chemistry has recently drawn the attention of sci- 

 entific men to many remarkable relations which exist between animated beings and the 

 inorganic world. For a long period, physiological doctrines, the spirit of which, for 

 many ages, has undergone but little change, offered an insurmountable barrier to the 

 application of methods of physical research to problems connected with the phenome- 

 na of life. On these, in our times, a successful inroad has been made, chiefly through 

 the aid of improved methods of chemical analysis. In a philosophical point of view, 

 it was the office of the seventeenth century to unfold the doctrine of universal gravita- 

 tion, to assign proper causes for the motions of the celestial bodies, and to develop the 

 great doctrines of astronomy. It was the office of the eighteenth to lay the founda- 

 tions of physics and chemistry, or of that group of sciences which embraces the rela- 

 tions and reactions of atoms. It is the office of the nineteenth to discover the laws 

 which obtain in the complicated structure of animated beings, those laws which give 

 rise to the mysterious phenomena which we call life. 



2. This book, in which will be found some facts which it has happened to its author 

 to discover, is offered as an humble contribution among those more brilliant gifts with 

 which Germany, and France, and England have lately enriched vegetable and animal 

 physiology. It treats of a subject which forms the connecting link between pure chem- 

 istry and those higher sciences. The great idea which it is designed to illustrate is 



A 



