BY MOLECULAR COALESCENCE. 51 
force, active inertia, and gravity. Now, if it be admitted 
that the size of this first crystal is such, that is, that its 
component molecules are so close together that they are 
all put in motion and afterwards brought into a state of 
rest by only one impulse; or, what is the same, that the 
impulse given to any one molecule could not for want of 
space be repeated, then no part of a curve could possibly 
enter into its contour, since this contour would on this 
supposition be made up only of the first material points of 
the curves which each of these molecules would describe 
separately, if it continued in motion under the conjomed 
effect of an impulsive and attractive force. As this 
explanation perfectly agrees with the earliest appreciable 
forms and appearances presented by crystallizable sub- 
stances in the act of crystallizing, and as I believe it is the 
only explanation which in principle can account for the 
rectilinear form of crystals, produced as they are under 
circumstances all tending to cause curvilinear arrangement, 
it may be inferred to be the correct one. It goes also to 
furnish conclusive evidence that the principle upon which 
this explanation is based, and the premises from which 
it has been deduced are real; and moreover it goes to 
show that several of the points which have only been 
assumed in the course of the discussion, or imperfectly 
demonstrated, are themselves facts. Now, after a primitive 
or first crystal has been thus formed, it can easily be 
conceived that, as a multitude of such crystals are all 
formed together at the same instant, they will be brought 
by the attraction of gravitation imto apposition, and the 
juxtaposition of their flat surfaces being favorable for 
extensive contact, they will be forcibly drawn together, 
and retained in the rectilinear form by the action of 
gravity, and thus larger rectilinear crystals will result, 
