Wadsworth.] 176 [April 16, 



weenawan Series where the lava rests on them. Further, this 

 lava mass is not a loose piece because it had not only indurated 

 the sandstone, but it was also found to extend across the stream 

 into both banks, and to underlie the conglomerate forming the 

 fifth fall of the stream ; while the detritus of this lava was dug 

 out of the base of that conglomerate by myself and is now pre- 

 served in the collections of the Museum of Comparative Zoology. 

 All this conclusively shows that the sandstone in question is a 

 constituent portion of the eastern sandstone, that it was overflowed 

 and indurated by the basaltic lava now lying there and admitted 

 to be a constituent portion of the so-called Keweenawan Series ; 

 and further that this lava flow was denuded and its detritus built 

 into the overlying conglomerate which in its turn was overflowed 

 by another lava stream. 



It is still maintained that this evidence, published with sufficient 

 fulness in 1880, 3 demonstrates that the eastern sandstone here 

 is a constituent part of the copper-bearing rocks and underlies 

 them ; also that the Keweenawan Series, as first established, has 

 no existence as a distinct formation older than the sandstone. 



It is to be distinctly remembered that Irving's evidence consists 

 solety in the fact that he has not seen, or negative evidence, while 

 mine is positive or a statement of things seen, and therefore by all 

 laws of evidence leads. In other words the whole question depends 

 upon this : did I see that which I affirm I saw or not? If I did, 

 and no one has proved that I did not, then the Eastern sandstone 

 underlies the copper-bearing rocks on the Hungarian and Douglass 

 Houghton Rivers, and the Keweenawan series, as now held, is an 

 impossibility. It can hardly be considered egotism if I claim, 

 considering the history of events since 1878, that my statement 

 that I have observed a certain fact is at least as good evidence as 

 the statement of some others that they have not seen the same. In 

 the district in question one of the favorite arguments advanced by 

 a number of observers in favor of the essential difference in age 

 between the eastern sandstone and the traps has been that the de- 

 trital rocks intercalated with the latter are largely composed of old 

 rhyolitic and trachytic debris, but that the eastern sandstone is 

 composed chiefly of quartz. Since the rhyolitic and trachytic ma- 

 terial is eruptive, its absence proves nothing regarding difference 



» Bull. Mus. Comp. Zool., vn, 113-116. 



