= ,es CR Fr es 
el 
A. A. Hayes on the Serpentine Rock of Proctorsville, etc. 385 
these so well known serpentines, I next chose as the subject of 
analytical trials the rock occurring in the township of Cavendish, 
village of Proctorsville, Vt. This mineral has been described as 
& serpentine, and its physical characters generally, entitle it to be 
so considered. It is traversed by thin white veins producing a 
variety in its otherwise deep green color. The averages of a. 
humber of samples are included in the following determinations. 
IV. 100 parts of the Proctorsville serpentine afforded— 
Moisture, . : i : ; ; 
Carbonic acid, : : ‘ : . Pee | fe 
Magnesia, . : 3 ; ; ‘ ° 16-00 
33°45 
. the cementing material, leaving 66°55 as basis rock, composed 
of— 
Combined water, , , é . : 6-21 
Silicie acid, . : : : a ee Gee Ae 
agnesia, . : : : : , : 18:70 
Proto-perox. iron and manganese, . re, PaO 
Alumina, . ; : - ‘ : ° 1:13 
Chrome iron, ; : : eee : ‘92 
99:91 
V. 100 parts afforded— 
uter, -. : : : - 5°60 
Carbonate of magnesia, . ; A : . 26°40 
is rock, : es ° 68-00 
100-00 
A number of similar determinations were made on the rock 
obviously composed of talc and compact asbestus, cemented by a 
small proportion of carbonate of magnesia, in an anhydrous state. 
The serpentine of New Fane also afforded carbonate of mag- 
Nesia, in variable proportions, whilst the so-called serpentine of 
Lynnfield was long since proved to be in part carbonate of mag- 
hesia, cementing a rocky base including argillite. Se 
everal European specimens, from unknown localities, were 
found to consist of associated magnesian minerals, cemented by 
” Stvoxp Serres, Vol, XXI, No. 63, May, 1856. 49 
