1881 .] 
271 
[Wadsworth. 
than the rhyolites, and are classed by King and Emmons as ande- 
sites. King in objecting to Zirkel’s determination of these speci- 
mens as basalts states : “ At the time Professor Zirkel’s examina- 
tions were made, the field-notes were not written out, and he was 
not informed as to the condition in the field ” (I, p. 573, II, p. 592). 
King’s statement, 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, and that Zirkel’s 
work w T as merely to describe the specimens that King had already 
classified. It is exceedingly unfortunate for the view of the 
independent conformation of the field and microscopic work that 
they should conform when Zirkel was informed as to King’s 
views, and disagree when he was not so informed. 
No. 608 (2006) is microscopically a rhyolite. 
Nephelite Basalts. 
No. 616 (646) I believe to be an andesite. -The presence of nephe- 
lite in it can hardly be considered as proved by Professor Zirkel’s 
method. Furthermore, claiming to have proved the presence of 
nephelite in this rock by its gelatinization when olivine was absent, 
he immediately assumes that he has proved, by the same method, 
the presence of nephelite in other rocks which contain olivine. 
While nephelite may be present in the andesites and feldspar 
basalts described on pages 255 to 258 of Zirkel’s report, it is 
claimed that it needs a more accurate and thorough method of 
research to establish its presence here, than that employed by 
Professor Zirkel. 
Clastic Rocks. 
No. 629 (2618), is described as an old clastic rock, but some 
mistake must have occurred here since 2618 is a volcanic rock and 
the section corresponds with it. 
Of the rhyolitic clastic rocks, Nos. 630 (574), 631 (703), 635 
(851) and some others contain fragments of andesite. Of the 
basaltic clastic rocks the section No. 667 (856) was probably not 
made from specimen Col. No. 856. 
