It 
be built up to fillspace. By shifting them relatively to one another, 
we may arrange them so that each brick touches fourteen other 
bricks. The most generalised figure which will fill space is one 
with fourteen plane faces and thirty six edges. Eight of these 
faces are hexagoned and six quadrilateral. Here again, by length- 
ening lines which are parallel to one another and by sloping 
the figure, other forms may be obtained which have the property 
of filling space. From this generalised figure all the other figures 
that fill space may be obtained by shortening one or more groups 
of parallel edges until they disappear. Thus we get the form with 
twelve faces, with four sides to each face. The cell of the hive-bee 
is half of such a form as this. All these properties were demon- 
strated by means of cardboard models, and the method of cutting 
the fourteen-faced form out of a solid block was demonstrated by 
slicing a Dutch cheese into the required shape. The properties 
of crystals show that their internal structure must consist of a 
pattern arrangement of the molecules, and so be related in some 
way to these simple space-filling forms. The form which has 
twelve four-edged faces is that involved in the piling of spheres 
in the way in which apples or oranges are piled in greengrocers’ 
shops, while the six-sided prism and the cube are related to other 
forms of piling. The external forms of crystals are, however, 
rarely such that they can be packed together without having 
any interstices. 
On Friday, February 3rd, the Annual General Meeting was 
held, under the presidency of Sir Samuel Wilks, Bart., F.R.S., the 
President. The Report of the Council was read and adopted. 
The President, Officers and Council were elected. 
The meeting was resolved into an ordinary meeting. 
Dr. Edward Shinton, M.R.C.S., L.R.C.P., gave a demon- 
stration of the ‘*Uses of X-Rays in Medicine.” 
Friday, March 2nd. Sir Samuel Wilks, Bart., F.R.S., President, 
in the Chair. 
Mr. J. H. Leonard, B.Sc., gave a lecture on ‘‘ The Natural 
History of Slate,’’ with lantern illustrations. The lecturer 
opened his remarks with a short review of the conditions of deposi- 
tion of sedimentary rocks and the meaning of the sequence in which 
they occur. Some of the agencies tending to alter sedimentary 
strata were then explained, the lantern slides shown in connection 
with this part of the subject bringing out the importance of field 
