Wadsworth.] 430 [October 3, 



specimen bearing on the label 913 " is evidently a basalt," but my 

 notes distinctly state that the rock is " dark gray." Here again 

 we have evidence that we have not the same hand specimen. Zir- 

 kel had, indeed, stated that the rocks from that region were light 

 gray, but I was unable to find any from the locality except this 

 dark gray one, which otherwise appeared macroscopically to answer 

 to his description ; and I stated what I thought that hand speci- 

 men to be. (M. 468, 469 ; W. 269.) 



APPENDIX. 



Owing to my paper not being reached in the printing of these Proceed- 

 ings until tlis present time, it has been, permitted me to bring it up to date 

 (March 1, 1884) by the addition of such evidence as has since been brought 

 out by the United States Geological Survey. 



Dr. Becker's completed work is now published and I have good reason to 

 complain that although he professes to give a history of the propylite dis" 

 cussion in this country, he ignores my prior published views on the question 

 completely; although he takes ground identical with them. 1 



In this work, besides the views previously quoted from his abstract, Dr. 

 Becker writes, in confirmation of my previously published statements, that 

 the quartz in some of the rocks determined by Zirkel as quartz-propylite 

 appears to him to be secondary. (Z. c. p. 85.) Again he says : "It was 

 found that even where a high degree of decomposition and a thoroughly 

 propylitic character prevailed, reasonably fresh rocks could be discovered 

 by diligent search . . . [and] they always proved andesitic. Where ande- 

 site dikes or overflows had been recognized and had been supposed to suc- 

 ceed propylite, careful examination and excavation showed that the change 

 was through a transition, not by contact." (/. c. p. 82.) In like manner 

 their relations to other rocks were traced until all the so-called propylites 

 were eliminated, but enough has previously been given from his earlier 

 published summary to convey his idea. He further points out many er" 

 rors in Zirkel's mineralogical determinations, but generally in such a way 

 that no one would observe the fact who was not carefully comparing the 

 two accounts. In order that the different views in the determination of the 

 same rocks may be seen at a glance, I give below a table showing the names 

 applied to the Washoe rocks by Zirkel, Becker, Merrill, and myself in the 

 order of their determination and publication. Omitting the difference in 

 nomenclature, owing to our diverse principles of classification, I do not see 

 but that the determinations of Dr. Becker and myself are in accord in al- 



1 Becker, Geol. Comstock Lode, pp. 12-31, 33, 81-90. 



