1891.] 
193 
[Dolbear. 
whether they can cohere or not will depend upon whether the vibra- 
tory rates are commensurate or not. If they are not there will be 
what is called interference in their respective fields and each will 
tend to destroy the other’s field. When the vibrations of two tun- 
ing forks not in unison or in a harmonic series, are heard together 
their interferences are audible and are called beats. They are in 
opposite phases a portion of the time. Vibrating atoms must be 
subject to the same conditions. One ought therefore to expect 
that elements with different masses should show different degrees 
of coherence, as indeed they do. There are all degrees of these 
incompatible movements from that exhibited by oxygen and fluo- 
rine which have never been made to combine at all, through the 
slight cohesions shown by gold, platinum etc. for other elements 
up to that exhibited by carbon for itself in the diamond and oxy- 
gen and aluminum in the ruby. 
Furthermore an element having but a small mass like hj^drogen 
could produce a. field of slight strength compared to that of an 
element moving with same velocity yet having decidedly a greater 
mass, so that when it combined with any other element it would 
be because of the greater energy of the other’s field, that is to say, 
oxygen holds on to hydrogen rather than hydrogen to oxygen, and 
one would, expect that hydrogen could be replaced by some other 
element in a compound more readily than any other element. 
Hence, whatever might be the relative rates of vibration when 
compared with other elements one might infer it could be asso- 
ciated with them. One might explain its weak affinities by its 
small mass and consequent small vibratory energy. 
With larger masses however, the case would be different ; if one 
made five vibrations while the other made but one, they would be 
in the same phase but one-fiftli of the time and in more or less in- 
terference the other four-fifths, and unless there was a con- 
siderable disparity in their masses there would apparently be but 
slight cohesion. If one made four while the other made one they 
would be in similar phases three-fourths of the time and could thus 
fortn a more stable alliance. 
As has already been said atoms vibrate in harmonic series and 
this must frequently modify the position of the nodes where ad- 
hesion can occur. Now, the simple harmonic series is 2, 3, 4 and 
so on times the fundamental rate. If one will imagine such a 
PROCEEDINGS B. S. N. H. 
VOL. XXV. 
13 
JAN. 1S9I . 
