* BY MOLECULAR COALESCENCE. 63 
lime by the first process. Hence it is evident that calculi 
thus composed of very dissimilar substances, held together, 
as is clear from their structure, by only a feeble attractive 
force, must owe their spherical figure chiefly to gravity. 
Consequently, when removed from the bottle in which they 
were formed—where all the molecules entering into the 
structure of each calculus would have been exactly balanced 
between the mutual attractions of the molecules themselves 
and that exerted upon them by the various parts of the 
bottle—to a small cell of glass, where they will be brought 
into much closer contiguity with surrounding objects, this 
balance will of necessity be destroyed, and the molecules 
being now attracted by the surrounded substances more 
forcibly than by one another, their separation will ensue. 
The vegetable component molecularly united with the 
carbonate of lime being exquisitely delicate, and conse- 
quently very light, as experiment shows, retains its form 
in consequence of its attraction of tenacity (which, how- 
ever, is only very feeble), being greater than the attraction 
of gravitation exerted upon it by surrounding objects, 
which attraction, considering the extreme tenuity of this 
residuum, can only be very feeble. And the earthy 
particles composing these calculi, being attracted by one 
another more forcibly than by the molecules of the 
vegetable residuum, become separated from it, and coalesce 
into globules. Now, as this explanation is perfectly in 
accordance with the laws of gravity and the attraction of 
tenacity, and as the conditions under which they act are 
within the reach of experiment and the results determinable 
by microscopic examination, it may be affirmed with cer- 
tainty that these forces would act as here shown. Hence 
there only remains one point to be determined, and that is 
the adequacy of these forces, under the present conditions 
