562 The Smithsonian Institution 



tinctively scientific method of investigation, and in the dis- 

 covery of two far-reaching laws of nature, namely, the law 

 of conservation of energy and the law of evolution of organic 

 forms. 



The scientific method is not new. It has been followed 

 more or less closely throughout the history of modern science. 

 From Galileo to Newton, from Newton to Laplace, from 

 Laplace to Darwin, the same method of patient observation, 

 of measuring, of weighing, of correlating, is discernible. But 

 it has now reached such a degree of definiteness, and its effi- 

 ciency in the search for truth is now so generally recognized, 

 that it has come to be known by common consent as the 

 scientific method. Subjects as diverse as philology and cos- 

 mogony, substances as different as zinc and protoplasm, 

 media as distinct as the air and the ether, systems as widely 

 separated as those of Sirius and Jupiter, have each been sub- 

 jected to the observation, the experiment, and the reasoning 

 which are characteristic of this method. By its aid, indeed, 

 almost every field of inquiry has been cultivated, and few 

 fields have failed to yield fresh accessions to knowledge. 



In the domain of the mathematico-physical sciences no 

 generalization of the period in question is comparable in 

 importance with that of the doctrine of energy. In this doc- 

 trine the earlier conception of the impossibility of perpetual 

 motion is replaced by the clearer and broader conception of 

 the impossibility of creating or destroying energy. All me- 

 chanical systems, and all of the varied mechanical phenomena 

 presented by the universe, are thus held to exhibit the com- 

 mon property of conservation of energy. It is to the recog- 

 nition of this law that are due in a large degree the recent 

 remarkable developments in the useful applications of ther- 

 modynamics, electricity, and magnetism; while the exigencies 

 of those developments have stimulated in a noteworthy man- 



