PROGRESS OF HUMAN KNOWLEDGE. 7 



truth. Such incongruities of belief belong to every 

 age ; but the counterfeit never gets the lasting stamp 

 of the genuine coin. The followers of these fancies 

 are prone to pass from one to another, allured by 

 novelty and more mysterious pretensions. It is a 

 matter of mental temperament ; and, after considerable 

 experience in life, I find myself generally able to in- 

 dicate the persons most liable to be thus deluded. Of 

 these mockeries of science the greater number in my 

 time have been of imported origin ; and it may further 

 be said that the most recent are the most preposterous 

 as offensive to religion as to science and common 

 sense. Happily the progress of true knowledge is little 

 retarded by these vagaries, which speedily efface one 

 another. Each is destroyed in turn by the same 

 credulity which begot it. 



This stricter demand for proof in every part of 

 modern science is at once a consequence and the cause 

 of experiment, as a main agent in research. The 

 simple history of experiment, in its negative as well as 

 positive incidents, is in itself a curious record of mental 

 progress. The necessities or uses 6f life must have 

 led the earliest and rudest races to tentative means, in 

 dealing with the raw materials of food, raiment, orna- 

 ment, and defence. But, even when we. come down to 

 the Greeks, we find no distinct recognition of the 

 nature and value of experiment; and encounter the 

 strange fact of a people subtle in observation and 

 thought, and aspiring to higher knowledge, yet failing 

 to seize upon a method so necessary, and seemingly so 



