CHAPTER XII. 

 The Great Unknown. 



A sailor lad, after his first voyage, having re- 

 turned to his country home, was eagerly beset for 

 wonders. "What hast t' seen in furrin parts?" 

 Among other things he reported having been 

 where the rum flowed like rivers, and sugar 

 formed whole mountains. At last, his inventive 

 powers being exhausted, he began to speak of the 

 shoals of tropical flying-fishes, a phenomenon 

 which his familiar sight had long ceased to regard 

 as a wonder. But here his aged mother thought 

 reproof needful ; raising her horn spectacles, and 

 frowning in virtuous indignation, she said, "Nae, 

 nae, Jock ! mountains o' sugar may be, and rivers 

 o' rum may be; but fish to flee ne'er can bel" 



Old Dame Partlet did only what philosophers in 

 all ages have done; she had formed her schedule 

 of physical possibilities, outside of which nature 

 could not go; nay, must not go. It so happened, 

 however, that old Dame Nature was obstreperous, 

 and refused to be confined within possibilities; 

 and the lawless fishes fly to this day, in spite of 

 Dame Partlet' s virtuous protest. 



There are several questions in natural science 

 which are questiones rexnttp, because a certain 

 amount of evidence of facts is on one side, and a 

 certain amount of presumption of impossibility on 

 the other. If eye-witnesses (or those who present 

 themselves as such) could decide the points, they 

 would have been decided long ago ; but those who 

 are believed to be best acquainted with natural 

 laws claim that theoretic impossibilities should 

 280 



