0'E.EiLLY — On the Occurrence of Serpentine at Bray Head, 509 
In estimating the loss on ignition, allowance has heen made for 
loss of CO2, and also for the change from PeO to FezOg. 
A quantitative analysis of the substance gives the following 
results : — 
per cent. 
SiOa 39-863 
CuO 0-180 
EeO 17-312 
AlA 10-070 
CrA 1-299 
MO 0-112 
CaO 6-380 
MgO 11-838 
J^'agO 1-289 
CO2 4-198 
Loss of weight at 110° C 0-430 
from 110° C. to 250° C. 0-129 
above 250° C. . . . 7-854 
100-954 
It is quite true that the composition here given differs from that 
of normal serpentine, in which the MgO is rarely under 25 or 30 °/° ; 
but Justus E,oth, in his work, Die Gesteins-analysen," gives at p. 56 
the following analysis : — 
1^0. 5. E'anzenbach near Dillenburg (analysed by Schnabel ; ex- 
tracted from Rammelsberg's ' ' Handworterbuch Mineralch." Suppl. 4, 
200, 1849), a very soft serpentine, oil-green colour. 
SiOa 41-70 
AlA 7-04 
Fe^Oa 
FeO 26-95 
MnO 
CaO 3-34 
MgO 10-26 
K2O, i^aoO 
H2O 11-58 
100-87 
Dried to 100° C. ; lost thereby 5*28 % H2O. 
