Eclipses 



separates known and scientifically-classified 

 things from the vast expanse of the unknown. 

 In this border zone the progress of science is 

 possible only thanks to fragile and temporary 

 hypothetical structures; but the work of the 

 scientist in this region is more active and more 

 profitable than in any other, for, to use the 

 words of Duclaux, "It is because science is 

 sure of nothing that it is always advancing/ 7 



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