THE CONSERVATION OF ENERGY 



it may not point the receptive mind of genius to new 

 and wonderful truths. 



MAYER'S PAPER OF 1842 



The paper in which Mayer first gave expression to 

 his revolutionary ideas bore the title of "The Forces 

 of Inorganic Nature," and was published in 1842. It 

 is one of the gems of scientific literature, and fortu- 

 nately it is not too long to be quoted in its entirety. 

 Seldom if ever was a great revolutionary doctrine ex- 

 pounded in briefer compass: 



' ' What are we to understand by ' forces ' ? and how 

 are different forces related to each other? The term 

 force conveys for the most part the idea of something 

 unknown, unsearchable, and hypothetical; while the 

 term matter, on the other hand, implies the possession, 

 by the object in question, of such definite properties as 

 weight and extension. An attempt, therefore, to ren- 

 der the idea of force equally exact with that of matter 

 is one which should be welcomed by all those who de- 

 sire to have their views of nature clear and unencum- 

 bered by hypothesis. 



"Forces are causes; and accordingly we may make 

 full application in relation to them of the principle 

 causa aequat effectum. If the cause c has the effect e, 

 then c = e; if, in its turn, e is the cause of a second ef- 

 fect of /, we have e = /, and so on : c = e = /...= c. 

 In a series of causes and effects, a term or a part of a 

 U-rm can never, as is apparent from the nature of an 

 :i, become equal to nothing. This first prop- 

 erty of all causes we call their indestructibility. 



"If the given cause c has produced an effect e equal 



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