658 Scientific Proceedings, Royal Dublin Society. 
1. Cases in which the influence of one assemblage A on the 
- general symmetry of disposition of the constituents of the mixed 
solid is predominant, these cases lying together at one end of the 
series. 
2. Cases in which the influence of the other assemblage B is 
thus predominant, these cases lying at the other end of the series. 
Now it is conceivable that if the discrepancy between the two con- 
stituent assemblages thus capable of intermixture is sufficiently great, 
the necessity for closest-packing will require one or other assemblage to 
predominate locally in the solidifying mass. For where there is such 
a discrepancy there will be a struggle in the mixed solidifying 
mass between its constituents, each seeking to impose on the mass. 
the arrangement proper to itself when unmixed, and the result will 
be that that form of arrangement which gains the upper hand 
will greatly favour the accretion of the constituent having this 
arrangement in preference to the other constituent, and will thus 
ensure a considerable preponderance of it throughout those portions 
of the mass in which it is thus in the ascendant. 
In such a case we must not look, as we pass along the series 
referred to, for a group of terms lying between the two classes 
named, and which belong to neither of them, but for a group of 
terms in which both classes appear side by side, one compensating 
the other, the liquid mixtures from which this group is formed 
being on the one hand richer in kind B than is the limiting case, 
with its maximum quantity of B, of those which furnish solely the 
symmetrical form dictated by A, and on the other hand richer in 
kind A than is the limiting case, with its maximum quantity of A, 
of those which give solely the form dictated by B. We shall not, of 
course, expect these limiting solid combinations to contain similar 
though opposite proportions of the two assemblages; it may be 
much easier for A to solidify than for B. 
The series of differently proportioned solid mixtures formed 
from such a series of liquid mixtures will in such a case contain a 
gap extending from the term with the greatest proportion of B 
capable of being contained in a mixed solid which has the general 
form of A, to the term with the greatest proportion of A capable 
of being contained in a mixed solid which has the general form 
of B. 
