Cli em ica I Science. — I */ •escott. 285 
essential features of the theory now established. It states the 
constitution of matter in terms that stand for things as they are 
made. The mathematician may choose the ratio of numerical 
notation, whether the ratio of ten or some other. But the chemist 
must find existing ratios of atomic and molecular mass, with such 
degree of exactness as he can attain. Chemical notation, the in- 
dex of the atomic sj'stem, is imperfect, as science is incomplete. 
However defective, it is the resultant of a multitude of facts. 
The atomic theory has come to be more than facile language, more 
than lucid classification, more than working hypothesis, it is the 
definit'toK of tin' knoirn truth in the existence of matter. 
The chemical atom is known, however, for what it does, rather 
than for what it is. It is known as a center of action, a factor of 
influence, an agent of power. It is identified by its responses, 
and measured by its energies. Concealed as it is. each atom has 
given proof of its own part in the structure of a molecule. Proofs 
of position, not in space but in action, as related to other atoms, 
have been obtained ])}• a multitude of workers with the greatest 
advantage. The arrangement of the atoms in space, however, is 
another and later question, not involved in the general studies of 
structure. But even this question has arisen upon its own chem- 
ical evidences, for certain bodies, so thaj; '-the configuration" of 
the molecule has become an object of active research. 
Known for w^hat it does, the atom is not clearly known for what 
it is. Chemists, at any rate, are concerned mainly with what can 
be made out of atoms, not with what atoms can be made of. 
WhatCA'cr they are, and by whatever force or motion it is that the}' 
unite with each other, we define them b}' their effects. Through 
their effects they are classified in the rank and file of the periodic 
system. The physicists, however, do not stop short of the phil- 
osophical study of the atom itself. Asa vibratory body its move- 
ments have been under mathematical calculations; as a vortex 
ring its pulsations have been assumed to agree with its combining 
power. As an operating magnet its interaction with other like mag- 
nets has been predicated as the method of valence. There are, 
as I am directlj' assured, ph3-sicists of penetration and prudence 
now looking with confidence to studies of the magnetic relations 
of atoms to each other. * Moreover, another company of workers, 
*"The results of molecular physics point unmistakably to the atom as 
a magnet, in its chemical activities." — A. E. Dolhear, in a personal com- 
munication. 
