nickel, : 
xyds of chrome, manganese, and loss, 
Soda and potash, : 
on ignition, = : zi e = 4°80 
100-00 
The ophiolites of Cornwall occur, according to De la Beche, 
among rocks of Devonian age. I have examined a clouded red- 
: rown and greenish serpentine, containing small —_ of 
es See said to be from the Lizard Point. It gave on 
analysis 
ilica, : : . : 40°40 : 
Magnesia, by Aiforene, - - - <4 ae ae 
Pro otoxyd of iron and oe - - - TAT 
Oxyd 6 of nickel, : z A : es 
_ Alumina, - y é é = 65 
Sie cai onions : a TNS 
100°00 
Thave examined specimens of the following serpentines with- 
out ee the presence of nickel; in their Cpe character 
11 of them resemble the Laurentian serpentin 
= Pale fe de Ley ee serpenting , from ae 
mn Philipstown, New York; me 
Dark olive-green ser egies from Munroe iron-mine, New 
Yorls contains patie of = but no chrome 
— 5. Pal ale green serpentine from oS Saaee ‘with ilmenite 
and magnetite; contains no chrom = 
_ 6. Yellowish green serpentine foc New bape bab ably of : 
- Setts ; density | 9551; this I have shown to be probably ot 
Devonian age.* a 
iolites have ponaral y been sogarded as i as intrusive rocks. : 
ithern Eur y occur in injec traversing the 
ted St eed strata, but they are also feo found i in — 5 hl 
i —— eens ae with SP ete 
t Te North Ari sere the oO Baer of the Laurentian, oie 
ind i i parently magnesian sedi-_ 
which have jennie in situ, and never so far 
.— xviii, p. 2 
