HERMANN VON HELMHOLTZ 



compatriot ; and the question of priority, which was 

 for a time keenly discussed by the friends of 

 both parties, was one that gave no concern to 

 his great mind. It is said that he bestowed even 

 more credit on Mayer than the latter claimed for 

 himself. 



The theory of the conservation of energy was 

 established experimentally by Colding of Copenhagen 

 and Joule of Manchester. The works of Sadi Carnot 

 (1824) and Clapeyron (^1833) in France in relation 

 to heat were also of first-rate importance. Carnot 

 had shown that work was done where heat was 

 transmitted from a body of a higher temperature to 

 a body of lower temperature. The Danish philo- 

 sopher was less of an experimenter than Joule, but 

 he expresses his conclusions in the following unmis- 

 takable language : 



' Force is imperishable and immortal ; and, therefore, 

 where and wherever force seems to vanish in perform- 

 ing certain mechanical, chemical or other work, the 

 force then merely undergoes a transformation and re- 

 appears in a new form, but of the orginal amount, as an 

 active force. 1 In the year 1843 this idea, which com- 

 pletely constitutes the new principle of the perpetuity 

 of energy, was distinctly given to me, the idea itself 

 having been clear to my own mind nearly four 

 years before, when it arose at once in my mind by 



1 Colding'i Treatise, 1843, Royal Society of Copenhagen. Theses con- 

 cerning Force. Nogle, Saetn'mger am Krtefterne. 

 50 



