76 
LUMMER. 
laws of nature, and of the Creator of all these wonders. To 
bring new phenomena and their producing forces within our 
established knowledge we have really not to explain , but to 
formulate them. Do you really know that our earth revolves 
about the sun, and why they attract each other according 
to Newton’s law? We can never really know this, and in- 
deed we shall consider ourselves fortunate when we shall 
have found that the Newtonian attraction requires time to 
influence an attracted body. We cannot know much about 
the real causes of natural forces; nevertheless we already 
know much about their laws. 
According to Herman von Helmholtz, our human na- 
tures must have believed a priori that the processes in nature 
are regularly and logically ordered and connected to each 
other by laws, or we would never have had the courage to 
undertake tedious and difficult research work. At the end 
of a long period of experimental work we feel confident in 
the relations which have been found to connect the observed 
phenomena. In order to reach the high standpoint to which 
natural science has brought us, we have had to abandon the 
old fashion of thinking out at the writing desk the mysteries 
of the world. In spite of Goethe’s sentence, “Und was sie 
Dir nicht offenbaren will, Das zwingst Du ihr niclit ab mit 
Ilebeln und mit Schrauben,” we have succeeded in finding 
the natural laws only by experimental study, by asking 
Nature questions and by compelling her to answer. Not long 
ago this manual labor “was completely scorned.” It will 
interest you to know that Helmholtz’s father, a Potsdam 
theologian, ridiculed his famous son, when he became a 
student of natural science, for entering so unworthy a pro- 
fession. It was not until the son was twenty-seven years old 
and a full professor of anatomy at Konigsberg, and earning 
more money than the old man, that father Helmholtz became 
reconciled to the research work formerly so heartily despised 
by him. 
At the present time salaries are paid by governments for 
research, and if they are not sufficient to make us wealthy, 
we get enough money to live upon, and, what is still more 
