630 EEPOET— 1892. 



importance of a new theory, and accept it in place of the one in which he has 

 been brought up, must stand at a height almost equal to that of the originator ? 

 The more startling and fresh the new conception the fewer must be those who are 

 ready to adopt it. But looking back at the history of science during the present 

 century, is there much evidence that great discoveries have been seriously delayed 

 by Avant of proper appreciation ? We may hear of cases where important papers 

 have been rejected by scientific societies, and occasionally a man of novel ideas- 

 may have been too much neglected by his contemporaries. I doubt whether 

 such cases of apparent injustice can ever be avoided, and, considering the great 

 changes involved in matters of primary importance, such as the undulatory 

 theory of light, the conservation of energy, and the second law of thermo- 

 dynamics, I cannot admit that there is much reason to be dissatisfi.ed with 

 the rate at which new theories have been received. Those wlio experience a tempo- 

 rary check, owing to the fact that public opinion is not ripe for their ideas, 

 are often fully rewarded after the lapse of a few years. The disappointment 

 which Joule may have felt during the time his views met with adverse criticisms 

 liom the official world of science was no doubt amply compensated by the pleasure 

 with which he watched the subsequent progress of research in the new domain 

 which his discoveries have opened out. 



The point is not one of academic interest only, for the fear of repressing some 

 important new discoveiy has a disastrous influence in another direction. The- 

 judgment of the scientific world seems to me to be tending too much towards- 

 leniency to apparently absurd theories, because there is a remote chance that they 

 may contain some germ of real value. A new truth will not be found to suffer 

 ultimately by adverse and even unreasonable criticism, while bad theories and bad 

 reasoning, supported by the benevolent neutrality of those to whose judgment the 

 scientific world looks for guidance, are harmful in many ways. They block the 

 way to an independent advance and encourage hasty and ill-considered generalisa- 

 tions. The conclusion I should draw from the considerations I have placed before 

 you are these : I believe that a reasonable censorship exercised by our scientific 

 societies is good and necessary ; that those whose fate it is to be called on to 

 express anopinion on some work or theory should do so fearlessly according to 

 their best judgment. Their opinion may be warped by prejudice, but I think it is 

 better that they should incur the risk of being ultimately found to be wrong than 

 that they should help in the propagation of bad reasoning. There is one matter, 

 however, on which all opinions must agree. AVorse than bad theory or logic is 

 bad experimental work. Should we then not rigorously preserve anj' influence 

 or incentive which encourages the beginner to avoid carelessness and to consider 

 neither time nor trouble to secure accuracy ? There is no doubt to my mind that 

 the prospect of admission to the Royal Society has been most beneficial in this 

 respect, and that the honourable ambition to see his paper published in the 

 ' Transactions ' of that society has preserved many a student from the premature 

 publication of unfinished work. 



One of the principal obstacles to the rapid dilTusion of a new idea lies in the 

 difhculty of finding suitable expressions to convey its essential point to other minds. 

 ^^'ords may have to be strained into a new sense, and scientific controversies 

 constantly resolve themselves into diflerences about the meaning of words. On 

 the other hand, a happy nomenclature has sometimes been more powerful thaa 

 rigorous logic in causing a new train of thought to be quickly and generally 

 accepted. 



A good example is furnished by the history of the science of energy. The 

 principle of the conservation of energy has undoubtedly gained, by the introduction 

 of the term ' potential energy,' a more rapid and general acceptance than it would 

 otherwise have received. A great theorem, which in itself seems to me to be 

 an intricate one, has been simplified by calling something energy which, in the 

 first place, is only a deficiency of kinetic energy. The only record I can find on 

 the history of the expression is given in Tait's ' Thermodynamics,' wherein the 

 term 'statical energy ' is ascribed to Lord Kelvin, and that of ' potential energy ' to 

 Baukine. It would be of interest to have a more detailed account on the origin of 



