96 
VICTOBIA MEMORIAL MUSEUM. BULLETIN NO. I 
The specimens as received by the writer are two in number 
and are excellent examples of vein formation. They present 
a nearly uniform thickness of 2 inches, and in one of the speci- 
mens there is evidence of some contortion. The principal con- 
stituents are the quartz and calcite as mentioned by Mr. 
English, and the preknite, which forms the chief motive of this 
article; in addition to these, a very few minute particles of a 
dark or nearly black mineral have been observed scattered 
sparsely through the vein; thin sections of the veinstone were 
examined by Professor Pirsson and Mr. Drysdale, of New Haven, 
Conn., and this dark mineral was shown by them to be axinite; 
no other minerals than those mentioned have been observed in 
these specimens. The most abundant mineral in the vein is 
a translucent quartz, all but white in colour, there being an 
almost insensible purplish tinge present. The quartz for the 
most part takes the form of groups of imperfectly defined 
crystals radiating from loci midway between the wall and the 
centre of the vein ; the individuals of these groups find, as might 
be expected, their greatest development towards the inner por- 
tions of the vein, and in many cases they terminate at the 
opposite wall; while, contrariwise, their development has been 
arrested in early stages of their growth. These groups are 
thus generally very irregular in their outlines; some show a 
semi-spherical outline, while others are more or less elongated 
in one direction and flattened or compressed in a direction 
normal to it. The calcite and the prehnite, which are approx- 
imately equal in amount, fill the interspaces between groups of 
quartz individuals. The calcite is white in colour and does not 
present any unusual characters. 
The Prehnite. 
As indicated above, the prehnite seems to be more intimately 
associated with the calcite than with the quartz. In the hand 
specimens the prehnite may be observed in small patches and 
reticulations up to one-fourth of an inch in width ; these to the 
unaided eye, or with a hand lens, appear to be homogeneous; 
in thin sections, however, they are seen to be contaminated 
with more or less calcite and some quartz; it has a rather in- 
