The sun., 1919-07-20

truth more and more firmly together INTO
a single edifice.
No other result indeed could have fol
lowed the discovery and demonstration of
the unified composition Of matter of every
sort, living tissue or that which We are
pleased to term inanimate; once we had
learned that every atom of each and all Of
the elements is made up of the tiny par
ticles of electricity called electrons and
that every natural phenomenon is explain
able by the behavior of these electrons the
artificial barriers men had tried to erect
to partition of knowledge into mutually
exclusive and detached cubbyholes van
ished in the light of the fundamental
truth that astronomer and geologist, chem
list and biologist, physicist and psycholo-
gist were all working in the same raw
material and all with the stuff that was the
everyday tool and commodity Of the cleo
trician.
How long period of time had elapsed
in the history of the human race between
the beginnings of mans search for truth
and the discovery of almost every es-
sential fact comprised in the body Of mod
ern scientific knowledge, and how swiftly.
once the true path had been found, the
body of knowledge grew and developed,
are strikingly and interestingly brought
out by Mr.. Mills in the Introductory
chapters that give the reader enough of
the history Of scientific research to enable
him the more clearly to understand and
more fully to appreciate the significance
Of the results latterly achieved. Absurd
and artificial as the scientific theories of
the ancient Greeks appear in the light of
the new knowledge, yet one who possessed
only such knowledge as was held at the be-
ginning Of the Christian era would find
himself to-day only a matter of three hun
dred years behind the times in knowledge
OF most of the important principles and
hardly half century out of date as to
nearly all the rest of them. 1t was not,
indeed, until the very end of the nine
tenth century that the electron was dis
covered, and while this discovery did not
alter but rather served to confirm the
truth of many Of the principles that had
heretofore been accepted, it necessitated
so many restatements Of old truths and the
rejection Of so many tentatively held the
ories that could not survive in the light Of
this fundamental fact that modern science
may fairly be said to date from it.
What is this electron, upon which all
modern scientific truths rest7 How does
one picture it, how describe itf Mere
figures convey little, so minute are the
fractions into which the tiniest particle of
visible matter must be subdivided before
we get down even to the atom, and the
electron is to the atom, as Sir Oliver Lodge
so graphically visualized it, "like the TIM
est gnat flying about inside of the hugest
cathedral" In q cubic centimeter of air
there are molecules equal in number to
81 multiplied by the nineteenth power of
ten; in other words, the number expressed
by writing eighteen ciphers after the num-
Der q! These molecules Of oxygen and
nitrogen are composed of atoms; the pre-
else size of the atom being matter of lit
tie consequence, but approximating the
fraction of a centimeter expressed by
writing the figure above the line and the
eighth power of ten, or one hundred mil
lion, below the line. Now, this atom con-
tains seven electrons in the case of nitro
gen, or eight in the case Of oxygen, each
electron being about hundred thousandth
Of the diameter of the atoml
Nv.
Huge as is the field within which the
electron is free to move within the atom
itself-a field which, were the electron Of
the size Of the earth, would compare with
the orbit Of this planet about the sun
electrons are constantly bursting out Of