66 FORMATION OF SHELLS OF ANIMALS, ETC., 
chemical action. Hence they can only be attributed to 
the molecular disturbance of the previously arranged and 
balanced molecules by the sudden addition and contact 
of fresh ones. This is no more than might have been 
expected ; indeed, it could not have been otherwise, if the 
cause on which the globular form of these bodies depends 
be the force of gravitation, and if the explanation given 
at the beginning of this paper be correct. One result of 
this experiment, the dusty appearance in the interior of 
many of these globules, arising from the disturbance and 
loss of balance of their molecules, shows that light is only 
perfectly transmitted by these spherical bodies when their 
molecules are arranged and adjusted on physical prin- 
ciples, and, therefore, that the forces by which their 
perfect balance is maintained are in some way connected 
with the propagation of the etherial undulations upon 
which light is supposed to depend, molecular confusion 
and opacity being the effects of the same cause. This 
fact is apparent in the form of disintegration preceding 
coalescence, as shown by the central opacity of incom- 
pletely formed globules, but it is much more strikingly 
displayed in the globules formed in this experiment. Also 
another fact is made by this experiment particularly pro- 
minent, which is the necessity of time in the operation 
both of coalescence and disintegration. In the formation 
of globules according to the ordinary process of coales- 
cence, everything takes place gradually ; the decomposi- 
tion, and consequently the formation, of the globular car- 
bonate being slowly effected, and the globules bemg slowly 
attracted towards one another, as can be shown by the 
microscope ; so that sometimes three globules lying near 
together can in some specimens be seen to have changed 
their shape before they are actually brought imto contact. 
