1882 .] 
457 
[Merrill. 
granite and diorite, and lithologically this would seem to me to 
be its exact position, with its orthoclase, mica, abundant quartz 
disseminated in a sort of groundmass on the one hand, and with 
its hornblende remains and plagioclase on the other hand. But 
the chief interest in citing this specimen is to notice that Mr. 
Wadsworth regards this as a “fine-grained granite, the same as 
the fine granite modifications of granite which can be seen at 
Rockport, Mass. These modified fine-grained portions of the 
Rockport granite are continuous with the main granite (coarse 
grained) mass.” 1 It will be seen here that Mr. W adsworth calls 
to his aid field relations to assist his lithological conclusions, 
an eminently rational thing to do ; but what seems strange is 
that he objects to this proceeding on the part of others. 2 
The diorites of Zirkel’s Report, Nos. 162, 172, 173, 185, 188, 
Mr. Wadsworth regards as “old and altered andestic rocks.” 3 
The first four of these seem to me to be true diorites of a more 
or less porphyritic variety. 4 Professor Zirkel has called No. 162 
a “ diorite porphyry.” But the thought occurs that this may be 
just what Mr. Wadsworth means by an “ old, altered andesite.” 
No. 188 has been mentioned by Zirkel in a sort of appendix 
fashion, at the end of the chapter on diorites ; his words are : 
“ At the close of these pages on diorites, a hornblende rock may 
be mentioned * * * it consists of quartz and hornblende in needles 
and prisms.” No notice appears to be taken by Mr. Wadsworth of 
Zirkel’s plain intention to distinguish between this peculiar rock 
and ordinary, genuine diorites. 
The diorite from the Kawsoh Mountains 5 Mr. Wadsworth 
regards as an “ old basaltic rock, a diabase, macroscopically and 
microscopically.” He moreover says that it contains some augite 
which was unnoticed by Zirkel. A good diorite might well carry 
1 These Proceedings, Yol. xxi, p. 255. 
2 For instance, in his second paper, page 271, he writes: “King’s statemant, then 
shows that the determination of the rock species was made by him, in general, and 
implies that Zirkel could not properly determine the species a rock belonged to unless 
he was informed as to its field characters. This further implies that there is no science 
in lithology,” etc. 
3 These Proceedings, Vol. xxt, p. 257. 
4 Section No. 172 is too much altered to be of service. It came from the same rock, 
I believe, as that furnishing section No. 173. No. 185 does contain augite remains as 
Mr. Wadsworth noticed (These Proceedings, Vol. xxi, p. 257). 
6 Not numbered in the Report. Section bears No. 162 (a), Col. No. 21,957. 
