Now, as has just been said, important likenesses between 
different kinds of grouping of the same set of balls are conceivable, — 
even where no enantiomorphous relations subsist, these likenesses 
being comparable to the resemblances which Hantzsch would place — 
under his heading II. Thus suppose that the same homogeneous — 
assemblage of balls, having the same arrangement, is symmetrically — 
partitioned’ in two different ways into group-units of the same 
composition by appropriate breaking of some of the links, the 
external balls of one kind of group being internal balls of the other 
kind of similarly-constituted group. Itis then evident that the 
properties of two liquid assemblages thus obtained may be widely 
different in many respects, and that at the same time one kind of 
assemblage may readily by a change of conditions be transformed 
into the other. And the same will be true of two assemblages 
which are thus related which have in the solid state not pre-_ 
cisely the same arrangement, but only approximately the same. 
It is further quite conceivable that the addition of certain 
balls in a homogeneous manner to one of the two assemblages 
may cause a change in the partitioning, 7. e., in the system of 
linking, which will convert it into an assemblage allied to the 
other of such assemblages. 
With this conclusion we may compare the fact that while 
bromomaleic acid is produced from fumaric acid and bromine, 
bromofumaric acid is produced from maleic acid and bromine, 
fumaric acid and maleic acid being isomerides.? This kind of — 
change is however, considered later.’ 
It is not difficult to perceive that homogeneous assemblages 
composed of spheres of different sizes packed as close as possible 
will generally have fewer points of contact when the symmetry 
is enantiomorphous than when the assemblages are identical with 
their own mirror-images, and consequently that the packing will 
generally be closer in the latter case; further, we see that where 
the closest packing possible under certain given conditions is very com- 
pact, it is less likely that some alternative arrangement will, when a 
slight change of conditions occurs, be found to be the closest, in other 
606 Scientific Proceedings, Royal Dublin Society. 
1 See p. 580. 
2 « Grundriss der Stereochemie,’’ p. 77. Comp. Holt, ‘‘ Berl. Ber.,’’ 24, p. 4129. 
3 See below, p. 685. 
