97 
and thus introduce confusion, and further, he has stated 
certain conclusions which, if I understand his statement, 
are certainly erroneous. 
Some of these errors were pointed out in the short dis- 
cussion which followed Mr. Gwyther’s paper and led him to 
append the final note. In this note which contains one 
correction further statements are made which I feel, if 
allowed to pass without comment with the rest of the 
paper, might tend very much to confuse the subject. I 
have therefore thought it desirable to make the following 
comment. 
It is stated on the top of page 37 that in one condition 
“ the centres of the spheres are the angular points of a net- 
work of regular octahedra.’’ This cannot be, as was pointed 
out in the discussion, since regular octahedra cannot 
completely occupy space, the intervening spaces being 
tetrahedra. 
At the end of the next paragraph the author says,— 
“ My object is to show that a given volume can be filled 
with the same set of equal spherical granules in different 
ways, and that if even the boundaries are fixed and rigid 
the difference would amount only to multiples of a gra- 
nule, and would not be expressed as a fraction of the 
whole mass.” 
At first sight it appeared to me that the author’s object 
had been to disprove the general proposition that I had 
stated, viz., a group of molecules holding each other in any 
uniform arrangement could not be subject to any uniform 
distortional strain without changing the mean density of 
the group* 
