692 T. C. CHAMBERLIN 
these qualities fit the general import of the evidence, but for the 
present it is prudent to leave the question of the state of the center 
to be settled in the future. It is to be observed that the increasing 
density of the interior tends to dampen the speed of the seismic 
waves, and that correction for this effect must be made in deducing 
the inward increase of rigidity and elasticity from the seismic 
records. When allowance is made for this, the generalization 
that rigidity and elasticity are notably higher in the interior than 
in the outer shell is put beyond serious question. ‘This means that 
in the partition of the compressional energy between those phases 
that increase the rigid elastic attachments of the molecules to one 
another and those phases that weaken or destroy these attachments, 
the former have been favored in a marked degree. This is testi- 
mony of a most cogent sort. By interpretation, this signifies 
that only a minor part of the compressional energy took the 
vibratory form in the interior, the major part taking the revolu- 
tional or constructive form, and that in doing this it served to 
promote compactness and the strength of hold of the constituents 
on one another. 
DID THE ORGANIZING ENERGY EFFECT CHANGES IN THE CONSTI- 
TUTION OF THE ATOMS? 
Lest the seeming needs of the case bias us toward one con- 
clusion rather than another, let us hasten to note that the mean 
density of the earth, compared with the probable density of the 
original matter, is such as to offer no real ground for bias in favor 
of atomic construction, for the higher density of the interior is 
fully accounted for by the density gradients that arise from meta- 
morphism in the zone of observation. Atomic construction, if 
invoked as an aid, might as easily render the interior mass too dense, 
as to help explain the density as it is. Nor is there more than un- 
certain evidence bearing on the atomic question; but the matter is 
too important to be ignored in a discussion of the effects of com- 
pressional energy. 
The most remarkable of known exothermal effects connected 
with rock-substance springs from the spontaneous atomic disinte- 
gration of the heaviest known elements. No evidence that this 
