598 FR A GMENTS F SCIENCE. 
public, than during the last thirty or forty years. I say 
"the general public," because it is a feature of our time 
that the man of science no longer limits his labors to the 
society of his colleagues and his peers, but shares, as far as 
it is possible to share, with the world at large the fruits of 
inquiry. 
The celebrated Robert Boyle regarded the universe as a 
machine; Mr. Carlyle prefers regarding it as a tree. He 
loves the image of the umbrageous Jgdrasil better than 
that of the Strasburg clock. A machine may be defined 
as an organism with life and direction outside; a tree may 
be defined as an organism with life and direction within. 
In the light of these definitions, I close with the conception 
of Carlyle. The order and energy of the universe I hold 
to be inherent, and not imposed from without, the expres- 
sion of fixed law and not of arbitrary will, exercised by 
what Carlyle would call an Almighty Clockmaker. But 
the two conceptions are not so much opposed to each other 
after all. In one fundamental particular they at all events 
agree. They equally imply the interdependence and. 
harmonious interaction of parts, and the subordination of 
the individual powers of the universal organism to the 
working of the whole. 
Never were the harmony and interdependence just 
referred to so clearly recognized as now. Our insight 
regarding them is not that vague and general insight to 
which our fathers had attained, and which, in early times, 
was more frequently affirmed by the synthetic poet than by 
the scientific man. The interdependence of our day has 
become quantitative expressible by numbers leading, it 
must be added, directly into that inexorable reign of law 
which so many gentle people regard with dread. In the 
domain now under review men of science had first to work 
their way from darkness into twilight, and from twilight 
into day. There is no solution of continuity in science. It is 
not given to any man, however endowed, to rise spontane- 
ously into intellectual splendor without the parentage of 
antecedent thought. Great discoveries grow. Here, as in 
other cases, we have first the seed, then the ear, then the 
full corn in the ear, the last member of the series implying 
the first. Thus, as regards the discovery of gravitation 
with which the name of Newton is identified, notions more 
or less clear concerning it had entered many minds before 
