1882 .] 
458 
[Merrill. 
Vol. v, No. 13. “ Some Points relating to the Geological Exploration of 
the Fortieth Parallel, by M. E. Wadsworth, Ph.D.,” Proc. Bost. Soc. Nat. 
History, Vol. xxi, Oct. 19, 1881. 
References to “ Zirkel’s Report ’’refer to Vol. vi of the Report of the 
Geological Exploration of the Fortieth Parallel. The specific title of the 
Report is : “Microscopical Petrography, by Ferdinand Zirkel.” 
In Mr. Wadsworth’s reply 1 to my first paper 2 upon this sub- 
ject, that gentleman cites what he considers as the two points of 
my paper which cover all of importance therein presented ; on page 
244 of Mr. Wadsworth’s paper are the words : “In both of these 
counts, which cover all of importance in Mr. Merrill’s paper, he 
has totally failed, on account of erroneous views regarding my 
statements and opinions.” These two counts as summarized by 
Mr. Wadsworth we find to be : — 
1° That Mr. Wadsworth had been mistaken in his use of the 
term “ original microfelsitic base,” since the original use of the 
term was different : hence that he was unqualified for his work, 
and had made his statements ignorantly. 
2° That his statements of what the .rocks are in the collection 
under discussion do not agree with my definitions of diorite, 
diabase, hornblende-porphyry, gabbro, basalt, andesite, etc. ; and 
therefore the same conclusion is to follow as in the preceding. 
The first half of the first point was indeed presented in my 
paper as an incidental criticism, namely, that Mr. Wadsworth 
had been mistaken, apjoarently, in his use of the term “original 
microfelsitic base,” and that from this and other points of evidence 
he seemed unfamiliar with the microfelsitic base in the Zirkel 
sense. 
The second count, as presented by Mr. Wadsworth, I think 
cannot be found in my paper, the whole burden of which was a 
protest against Mr. Wadsworth’s method of making the most 
sweeping charges against a work in which our American litho- 
logical students are deeply interested, generally without adduc- 
ing evidence or giving a single reason for the charges of error 
1 These Proceedings, Vol. xxi, p. 243, “Some Points relating to the Geological 
Exploration of the Fortieth Parallel, by M. E. Wadsworth, Ph.D.” 
2 Concerning the Lithological Collection of the Exploration of the Fortieth Parallel, 
by N. F. Merrill.” These Proceedings, Vol. xxi, p. 234, 
