20 JOURNAL OF THE 
ture of the atom and like it invariable ; or whether this ability 
is variable and with it the nature of the atom itself.” 
It is not strange that this line of reasoning should lead 
Lothar Meyer to doubt the unvarying nature of the atom it- 
self, and thus losing his grasp upon one invariable to make 
sure of another. He says: ‘‘It is by no means impossible 
that the magnitudes which we now style atoms, may be va- 
riable in their nature.” 
It will be an unfortunate day for chemists when the belief 
in the unchanging atom is given up. Chaos will indeed enter 
into all of our theories when this, the foundation rock, is left 
at the mercy of every shifting tide of opinion and can be 
shaken by all manner of unfounded hypotheses. 
The case cannot be so hopeless as to necessitate calling to 
our aid so dangerous a doctrine. Before turning to such an 
expedient let us first make all possible use of our atomic the- 
ory asitstands. The extension of this theoiy teaches that 
the atoms are endowed with motion and this motion 
probably varies in velocity and phases with the different ele- 
ments. So too when the atoms unite the resulting molecule 
has a certain motion peculiar go it while the atoms composing 
it have an intra-molecular motion in which their original mo- 
tions are probably modified by their influence upon one an- 
other, It is quite manifest then that a molecule, in order to 
exist, must maintain a certain equilibrium and harmony be- 
tween these various motions, and that there can be all degrees 
of equilibrium from the very stable to that which may be up- 
set by the least disturbing influence from without. 
It seems to me that herein we have a full and satisfactory 
means of explaining the various problems connected with the 
conception of valence. ‘The question as to whether the atoms 
of two elements will unite is decided by affinity, which is in 
some way connected with the electrical condition of these 
atoms. ‘There is no apparent connection between this and va- 
lence. ‘The number of atoms which enter into combination 
forming one molecule is purely a matter of equilibrium and is 
dependent upon the motion of those atoms. ‘Thus a phospho- 
rus atom unites with chlorine atoms because of acertain affin- 
