302 Notices respecting New Books. 
On these alternate layers of 36 and 25 are placed till the height 
equals the base, that is, a cube is formed—the atoms represented 
by the balls being kept in their place by attraction. He then 
shows by appropriate figures that all the crystals exhibited on the 
face of the alum “ may be satisfactorily derived from a series of 
spheres maintaining that relative position which they must as-" 
sume if endued with the power of mutual attraction.” ‘* The 
surfaces and lines of the solids produced, are in no instance inter- | 
rupted, or broken, by a space equal to the diameter of one par- 
ticle. Will any other geometrical solid furnish as simple and” 
satisfactory a solution?’ The cube assumed as the integrant 
particle is demonstrated to be defective. 
“ But there are many substances in nature resolvable, both by 
mechanical division and chemical solution, into regular solids, 
which, it is evident, cannot in any way be constructed of spheri- 
eal particles. The rhomboids, for instance, of carbenate of lime, 
and the flattened octohedron produced by the action of water 
upon a four-sided prism of sulphate of magnesia. Is the theory 
calculated only to resolve the peculiarities of the former class ; 
or may it be extended by similar observations so as to include 
crystalline arrangements of every description ? g 
“<¢ The latter of the two substances just instanced, would seem. 
at once to point to a flattening of the elementary sphere, as af= 
fording a solution of the problem, with respect to its i aoe 
properties ; but how far may this idea be generalized? And ar 
there any peculiarities in this class of bodies, which may direct 
us to this explanation of their nature ?”’ 4 
Mr. Daniell then shows that spheroids may be so arranged as 
to yield all the forms and modifications which are the subject of 
inquiry, and concludes his ingenious paper as follows : 4 
«* A singular confirmation of the spheroidical form of the ultil 
mate particles of crystallized bodies, offers itself in the contem= 
plation of a local arrangement which is common to crystals of 
every substance. If we suppose two nuclei to be formed in am 
solution, in such a manner that the axis of one shall run in @/ 
contrary direction to the axis of the other, each will of course at= 
tract aparticular system of particles from the surrounding medium, 
Should the two, therefore, come in contact, a greater number 
will be collected at the point of junction than at any other, and 
they will therefore arrange themselves in the least possible spacey 
Accordingly we find, that whenever a crystal is attached to an= 
other, in such a manner that their axes run in contrary direc= 
tions, if we pull the two asunder, we shall invariably be presented 
with a regular hexagonal arrangement at the point of junction, 
whatever be the form of the crystal, the nature of the substance 
or the direction in which at any other part it would be disposed 
