White limestones of Sussex Co., JV. J. — Nason. 249 
to the white limestones. He now calls the rocks of the Highlands 
Azoic. His classification probably in an ascending series is •• 1st 
gneiss; 2d hornblende micaceous, feldspathic, and quartzose schists; 
3d white crystalline limestoneSj (saccharoidal marbles) interstrati- 
fied with seams or layers of magnetic ore (magnetite) and iron 
pyrites." 
One has rather to gness at his position ^than to gain a positive 
idea from his statements. 
On pp. 138 and 139, however, he notes that when a knob or 
outcrop of white limestone occurs in the blue, it is always accom- 
panied by dykes of granite and other igneous rocks. He also notes 
the presence of an increased number of minerals. On page 142 
Dr. Kitchell writes in such a manner as to leave one in utter doubt 
as to his attitude on this question, unless l^e regards it as possible 
that rocks belonging to his metamorphic series might have escaped 
alteration and to have come down to us almost wholly unchanged 
while others were highly modified. 
In speaking of the limestones of the southeast foot of Pochuck 
mountain, he says : ' ' There are portions (i. e. of the limestone) 
which are but partially altered ; the stone in part retaining its 
original color, but generally containing impurities. Other portions 
still are of a blue color, containing here and there a little calcite, 
in which there is considerable plumbago. In the parts which are 
but slightly altered, the texture ranges from compact to subcrys- 
talline ; and in those which are more completely changed, from 
sub-crystalline to that which is completely crystalline, thus pass- 
ing by regular gradations from ordinary blue limestone to that 
which is highly metamorphic." Rogers nowhere made a stronger 
statement than this and }-et Dr. Kitchell distinctly classifies these 
white limestones with the gneisses. 
As was before remarked the only avenue of escape from a flat 
contradiction in the same report is through the avenue which was 
suggested, namely, considering that the blue limestones as well as 
the white belonged to the same metamorphic series. Dr. Cook, 
however, who was Dr. Kitchell's assistant, cuts off even this 
avenue of escape, for in his (Dr. Cook's ) report for 18GS he 
says : — 
"The true position and identity in age of the crystalline lime- 
stone and gneiss was proved by Vanuxem and Keating, in L822, 
and this view has been sustained by all the observations of Dr. 
