386 THE POPULAR SCIENCE MONTHLY. 



when the obscure young student, in no way conscious of his future 

 pontificate, takes his degree (standing twenty-third on the list of 

 graduates), we should probably find that he had already elaborated 

 certain novel ideas about the undulatory theory of light, which he 

 at any rate promulgates a few years later, and afterward, pressed 

 with many difficulties, altered, as we now know, to an emissive one. 



Probably, if we could have heard his own statement then, he 

 would have told how sorely tried he was between these two opin- 

 ions, and, while exxDlaining to us how the wavering balance came 

 to lean as it did, would have admitted, with the modesty proper 

 to such a man, that there was a great deal to be said on either 

 side. We may, at any rate, be sure that it would not be from the 

 lips of Newton himself that we should have had this announced 

 as a belief which was to be part of the rule of faith to any man of 

 science. 



But observe how, if Science and Theology look askance at each 

 other, it is still true that some scientific men and some theologians 

 have, at any rate, more in common than either is ready to admit ; 

 for at the beginning of this century Newton's followers, far less 

 tolerant than their master, have made out of this modest man 

 a scientific pontiff, and out of his diffident opinions a positive 

 dogma, till, as years go on, he comes to be cited as so infallible 

 that a questioning of these opinions is an offense deserving ex- 

 communication. 



This has grown to be the state of things in 1804, when Young, 

 a man possessing something of Newton's own greatness, ventures 

 to put forward some considerations to show that the undulatory 

 theory may be the true one, after all. But the prevalent and 

 orthodox scientific faith was still that of the material nature of 

 light ; the undulatory hypothesis was a heresy, and Young a here- 

 tic. If his great researches had been reviewed by a physicist or a 

 brother worker, who had himself trodden the difficult path of dis- 

 covery, he might have been treated at least intelligently ; but, 

 then, as always, the camp-followers, who had never been at the 

 front, shouted from a safe position in the rear to the man in the 

 dust of the fight, that he was not proceeding according to the ap- 

 proved rules of tactics ; then, as always, these men stood between 

 the public and the investigator, and distributed praise or blame. 



If you wish to hear how the scientific heretic should be rebuked 

 for his folly, listen to one who never made an observation, but, 

 having a smattering of everything books could teach about every 

 branch of knowledge, was judged by himself and by the public to 

 be the fittest interpreter to it, of the physical science of his day. 

 I mean Henry Brougham, the future Lord-Chancellor of England, 

 the universal critic, of whom it was observed that, " if he had but 

 known a little law, he would have known a little of everything." 



