498 HISTORY OF OPTICS. 



undertaking allows, of those points of the undula- 

 tory theory which are still under deliberation among 

 mathematicians. With respect to these, an inti- 

 mate acquaintance with mathematics and physics 

 is necessary to enable any one to understand the 

 steps which are made from day to day; and still 

 higher philosophical qualifications would be requi- 

 site in order to pronounce a judgment upon them. 

 I shall, therefore, conclude this survey by remark- 

 ing the highly promising condition of this great 

 department of science, in respect to the character 

 of its cultivators. Nothing less than profound 

 thought and great mathematical skill can enable 

 any one to deal with this theory, in any way likely 

 to promote the interests of science. But there ap- 

 pears, in the horizon of the scientific world, a con- 

 siderable class of young mathematicians, who are 

 already bringing to these investigations the requisite 

 talents and zeal; and who, having acquired their 

 knowledge of the theory since the time when its ac- 

 ceptation was doubtful, possess, without effort, that 

 singleness and decision of view as to its fundamental 

 doctrines, which it is difficult for those to attain 

 whose minds have had to go through the hesitation, 

 struggle, and balance of the epoch of the establish- 

 ment of the theory. In the hands of this new gene- 

 ration, it is reasonable to suppose the analytical 

 mechanics of light will be improved as much as the 

 analytical mechanics of the solar system was by the 

 successors of Newton. We have already had to notice 



