NATURAL VEESUS SUPEENATUEAL 47 



making his deductions. But if one Ascidian, and 

 but one, could be found whose heart beat like that 

 of other animals, that would be a puzzle to him. 

 Or if one comet, and only one, should appear carry- 

 ing its tail toward the sun instead of from it, com- 

 etary astronomy would be reduced to chaos. A float- 

 ing feather is no exception to the law of gravitation, 

 but a floating stone and a falling feather would be 

 an exception. Science as well as experience finds ex- 

 ceptions to general rules everywhere, but these excep- 

 tions are constant and as strictly the result of natural 

 law as anything else. Faith in the continuity of 

 nature, upon which the scientist builds, no less than 

 every man in the conduct of his life, does not mean 

 sameness or identity of all physical processes, but it 

 means identity of these processes under like condi- 

 tions. Given the same conditions, and the same 

 results always follow. Water obeys its laws under 

 low temperature, and iron its. It is not long since 

 that the Bishop of Carlisle urged as an argument 

 against the uniformity of nature the fact that the 

 weather is changeable ! If his lordship could have 

 shown that the laws which govern the formation of 

 clouds, and the precipitation of rain and snow are 

 changeable, or ever work inversely, he would have 

 made out his case. The fathers of the church be- 

 lieved that the flesh of the peacock never decayed. 

 St. Augustine said he had ascertained by experi- 

 ment that this is a fact. If this were so, it would 

 indeed be a remarkable exception ; but the man of 

 science would at once set about ascertaining its 



