86 Review of Owen’s Geological Report on Wisconsin, Iowa, etc. 
’ heating with oxalate of ammonia is always formed, into chlorid 
of potassium, evaporated, heated and weighed. It gave 0:1602 
grs. chlorid of potassium. ‘T'he composition of this apophyllite 
is therefore : 
I,MandIv. I, Wand Iv. 
> 52°69 
Mean. 
SiOg 52°51 52°60 contains oxygen 27°18 
CaO - 24°99 24:77 24°88 ig 7-08 
KO = - 514 514 514 w 0°87 
Fl - - 1°79 163 171 
HO . - 16°67 16°67 16°67 14°81 
10 
Oxygen equiy. with Fl= 0°76 
100-21 
Not taking any fluorids into calculation but their equivalent oxyds, 
the ratio of oxygen, KO:CaO:SiOs: HO=0-87:7-1:27:1:148 
or almost exactly what Berzelius found, : 8°: 30 Sam 
giving the formula KO, 2Si03+8Ca O, SiO3+16HO. 
It is not improbable that a variable quantity of oxygen may be 
replaced by fluorine and that the general formula is: ; 
K(0O, Fl), 2Si(O, F'l)s + 8Ca(O, F'1), Si(O, Fl) + 16HO. 
4, Allanite from Orange County, N. Y.—I find a statement in. 
Dana’s Mineralogy, p. 681, based upon an analysis of T. H. Gar- 
rett, that the massive pitch-black mineral from Orange County, 
which had been considered an allanite, did not contain any cerium. 
I am indebted to W. 8. Vaux, Esq., for a specimen from this local- 
ity. Mr. Edw. L. Reakirt analyzed it in my laboratory and found 
that it contains both oxyds of cerium and lanthanum, After the 
silica and alumina were separated as usual, the residue, insoluble 
in caustic potash, was boiled with oxalic acid and the white crys 
talline precipitate filtered after cooling. This oxalate on ignition 
yielded a reddish brown oxyd, from which nitric acid, diluted with 
about 200 parts of water, extracted a small quantity of lanthana. 
The remaining oxyd gave all the characteristic reactions of ce- 
rium. ‘The mineral from Orange County is therefore allanite. 
(To be continued.) 
ee ed 
Arr. XIl—Review of the Geological Report on Wisconsin, 
Iowa and Minnesota, and incidentally of a portion of Ne 
braska Territory. 
In our March number of this year, we gave a brief biblio- 
graphical notice of this work, soon after it issued from the press; 
but being the final Report of an important and very extensive 
Benlogica’ exploration of the Northwest, commenced in 1847 by 
2), 
to givea more extended review of the important geological facts 
and practical results than our space then admitted. This we 
