strike and most variable in dip.

I made with really great care (and in MS. in detail) observations on a case
which I believe is new, and bears on your view of metamorphosis (page 149,
at bottom). (Ibid., page 149.)

(FIGURE 7.)

In a clay-slate porphyry region, where certain thin sedimentary layers of
tuff had by self-attraction shortened themselves into little curling
pieces, and then again into crystals of feldspar of large size, and which
consequently were all strictly parallel, the series was perfect and
beautiful. Apparently also the rounded grains of quartz had in other parts
aggregated themselves into crystalline nodules of quartz. [Figure 7.]

I have not been able to get Sorby yet, but shall not probably have anything
to write on it. I am delighted you have taken up the subject, even if I am
utterly floored.

P.S.--I have a presentiment it will turn out that when clay-slate has been
metamorphosed the foliation in the resultant schist has been due generally
(if not, as I think, always) to the cleavage, and this to a certain degree
will "save my bacon" (please look at my saving clause, page 167) (542/2.
"As in some cases it appears that where a fissile rock has been exposed to
partial metamorphic action (for instance, from the irruption of granite)
the foliation has supervened on the already existing cleavage-planes; so,
perhaps in some instances, the foliation of a rock may have been determined
by the original planes of deposition or of oblique current laminae. I
have, however, myself never seen such a case, and I must maintain that in
most extensive metamorphic areas the foliation is the extreme result of