1901 - 2 .] J. G. Goodchild on Scottish Mineralogy . 
341 
foreshadowing of coming events, and as if the crystal aggregate 
were being laid down upon predetermined lines with the ultimate 
intention of building one large crystal upon the foundation con- 
stituted by an aggregate of many smaller ones. Be that as it may, 
the fact is worthy of attentive consideration, which may eventually 
lead to a fuller knowledge than we possess at present of the laws 
regulating growth in the inorganic world. Coplanar faces are 
shown upon figs. 11, 12, 14, 15. 
An inspection of the accompanying figures of Cerussite (which 
are all taken from registered specimens in the Scottish Mineral 
Collection) may serve to make these points clearer. I will only 
add, in concluding this paper, that the symbols employed are those 
used by Dana. These are excellent in their way, but if we were 
to adopt a uniform set of symbols for each of the more commonly 
occurring forms it would be a great improvement upon the system 
(or want of system) at present in use. I would suggest that the 
Unit Octahedron {111} in all minerals should be lettered o ; that 
the Unit Macrodome (or its equivalent form) {101} should be 
denoted by d; and the Unit Brachydome (or its equivalent form) 
{011} should always have the symbol e. {100, 010, 001} and 
{110} are already provided for by a nearly universal employment 
for them, respectively, of the symbols a, b , c, m. We might go 
further in the same direction with advantage. 
( Issued separately November 15 , 1902 ) 
