MATHEMATICAL PHYSICS. 521 



cheques in this manner; or, to put the matter In ;i more dignified 

 form, how comes it that, in the words of Schiller,* 



• MH (inn (.'cuius Btehl die Natur im ewigen Bunde, 

 \\;ih der eine verspricht, leistet « I i « ■ andre gewiss'? 



The question is as old as Bcience, :i n< I the modern tendencies with which 

 we have been occupied have only added point to it. II is plain that 

 physical science has do answer; its policy indeed has been to retreat 

 from a territory which it could aot securely occupy. We are told in 

 some quarters that H is vain to look for an answer anywhere. But the 

 mind of man is aol wholly given over t< ( physical science, and will aot 

 lie content forever to leave the question alone. It will persisi in its 

 obstinate questionings, and, however hopeless the attempt to unravel 

 Hie mystery may lie deemed, physical science, powerless to assist, has 



no righl to condemn il. 



I wonld like, in conclusion, lo read to you n characteristic passage 

 from thai address of Stokes in L862 which has formed the starting- 

 point of <his discourse : 



"In this section, more perhaps than in any other, we have fre- 

 quently (o deal with subjects of a very abstract character, which in 

 many cases can be mastered only by patient study, at leisure, of what 

 has been written. The question may not, unnaturally he ai I ed, IF inves- 

 tigations of this kind can best he followed by quiet study in one's own 

 room, what, is the use of bringing them forward in a sectional meeting 

 at all? I believe that good may he done by public mention, in a meet- 

 ing like the present, of even somewhat, abstract investigations J hut, 



whether good is thus done, or the audience merely wearied lo no pur- 

 pose, depends upon the judiciousness of the person hy whom the inves- 

 tigation is brought forward." 



It might be urged that these remarks are as pertinenl now as they 

 were forty years ago, hut I will leave them on their own weighty au- 

 thority. I will not myself attempt lo emphasize them, le I wme of 

 my hearers should \><- tempted io vc\<>r\ that the warning mighl well 



he home in mind, not only in the ordinary proceedings of the section, 



hut, in the composition of a, presidential address! 



Applied by Herechel to the discovery of Neptune. 



