10 INTRODUCTION. 



same primary substances are present on those num- 

 berless celestial bodies which a clear night reveals to 

 us, where we know that changed conditions continu- 

 ously cause new combinations to be formed between 

 these elements, where we know that infinitely small 

 quantities of living matter are able to transform large 

 quantities of non-living matter to living one, and where 

 finally we know also that some elements at least, can 

 directly give rise to other ones, it is not too risky to 

 conclude that whatever we see the revelation of every 

 day as Prof. BOSSCHA used to express it, is nothing 

 but the continuous transformation of that one or of tho- 

 se few wonderfull primary substance(s), from which 

 everything, ourselves included, originated. 



How? 



As yet we know but little about it. 



Physicists, chemists, geologists and biologists, all of 

 us, lift but the tips of the dense veil which hides the 

 mysterious workshop of nature, and but all too fre- 

 quently we have to thank those who come after us 

 for letting the tip, we lifted, fall down again, to hide 

 the errors we committed. But not-withstanding all 

 our stooping, we who try to reveal the underlying 

 secret of nature, feel, even in the midst of our defeats, 

 that the fundamental idea on which all our efforts are 

 based, that the conception of continuity in all what 

 happens, that the Principle of Evolution, which owes so 

 much to Charles Darwin, is correct that, as he expressed 

 it, the ,,ordinary succession by generation has never 

 once been broken". 



