98 SCIENTIFIC THOUGHT. 



of discovery and as to the real points at issue have 

 arisen. The history of thought only takes note of these 

 in so far as they are indications of what was of real 

 (not of personal) interest in the process, and are thus 

 a measure of the value which was inherent in its 

 development. 



None of the different views or theories with which the 

 earlier generations of philosophers during the century 

 operated seemed sufficient to give an insight into the 

 real essence, the 0u<nc, of natural phenomena. Neither 

 the astronomical nor the atomic nor the kinetic view 

 was all-embracing. On the Continent, both in France 

 and in Germany, the sciences were rigidly marked off 

 from one another, the connecting links were few and 

 ill-defined, and speculations as to the general forces and 

 agencies of nature were left to metaphysicians and treated 

 with suspicion. In England alone the name of natural 

 philosophy still obtained, and in the absence of separate 

 schools of science, such as existed abroad, suggested, 

 at least to the self-taught amateur or to the practical 

 man, the existence of a uniting bond between all natural 

 studies. It is significant that the term under which we 

 now comprise, and by which we measure, all natural 

 agencies, the term Energy, was first distinctly used in this 

 The term sense by Dr Thomas Young in his lectures on Natural 

 by Young. Philosophy, 1 a course which, be it noted, also embraced 



edition of the 2nd vol. of Clausius, 

 1 Die mechanische Warmetheorie ' 

 (Braunschweig, 1879), p. 324, &c. 

 In the labyrinth of these contro- 

 versies I have found Helm a fair 

 and conscientious guide. 



1 Vol. i. p. 59 of the edition of 

 Kelland. Young says :" The term 



Energy may be applied, with great 

 propriety, to the product of the 

 mass or weight of a body into the 

 square of the number expressing 

 its velocity. . . . This product has 

 been denominated the living force 

 (the vis viva), . , . and some have 

 considered it as the true measure 



