176 DR. THOMAS STERRY HUNT ON THE 
an interval concealed by soil, “ first, a marly shale, then mixtures with more carbonate of 
lime, some compact, some crystalline, some confusedly aggregated, presenting cavities 
lined with crystals of that mineral, and containing also sulphate of strontian in the mass, 
and in the cavities. With these, and above these, are other aggregates like serpentine, 
marble, etc., with purplish shale or slate, which are followed by a green and blackish trap- 
like rock, as to appearance, but too soft for that rock.” After this, that is, above it, is a 
mass which resembles the material overlying the lower beds of gypsum, and this last is 
covered by the upper porous dolomite. 
§ 31. In a supplement to the report of 1839, above quoted, it is added, “the green and 
trap-like rocks observed near the top of the hill to the east of Syracuse, have been examined, 
so far as time would admit. They are all serpentines, more or less impure, and of various 
shades of bottle-green, black, gray, ete. They all produce sulphate of magnesia with oil 
ofvitriol. . . . Some have a peculiar appearance, like bronze, owing to small gold- 
like particles, with a lamellar structnre, resembling bronzite or metalloidal diallage ; also 
other particles highly translucent, like precious serpentine, with frequently small nuclei 
resembling devitrifications or porcellanites, colored white, yellow, blood-red, variegated, 
_ ete. The grain of this is like common serpentine. In other kinds, the mass seems to be 
made of small globuliforn concretions, varying in size, being centres of aggregation. Some 
are of dark vitreous serpentine, others of the compact kind, the enveloping part of a 
light color.” 
Vanuxem’s farther notes, in his final report, add some important details to the above. 
He says: “ The great mass of entirely altered rock is a well-characterized serpentine, espe- 
cially when examined by the microscope.” He mentions, moreover, the occurrence of mica, 
both white or light-colored and black, besides accretions which he compares to granite, and 
others in which a hornblende takes the place of mica, forming aggregates resembling 
syenite. He also describes granular carbonate of lime, like marble in texture, which “ ex- 
isted as accretions or nodules, enveloped in the serpentine.” 
§ 32. I endeavored many years since to obtain specimens of these rocks, and through 
the kindness of Prof. James Hall secured a single mass of the serpentine, which contained 
small plates of a copper-colored bastite or bronzite. Neither mica, hornblende, nor any 
other crystalline silicate was however present in the mass, which was a well-defined ser- 
pentine, with some admixture of carbonates. It agrees closely with the description given 
by Vanuxem, being an aggregate of grains and rounded masses of serpentine, with others of 
a fine-grained carbonate of lime, imbedded in a greenish-gray calcareous base. The colors 
of the serpentine vary from blackish-green to greenish-white ; it is often translucent, and 
takes a high polish. An average portion of this rock gave to acetic acid, 34.43 parts of car- 
bonate of lime, and 2.73 of carbonate of magnesia, with 0.34 of iron-oxyd and alumina, 
leaving a residue of 62.50 of insoluble silicate. This was a nearly pure serpentine, as 
shown by its analysis. It was completely decomposed by sulphuric acid, and gave silica, 
40.67 ; magnesia, 32.61 ; ferrous oxyd, 8.12; alumina, 5.13; water, 12.77—99.30. No traces of 
either chrome or nickel could be detected. One of the small imbedded calcareous masses 
or concretions found in this serpentine was finely granular, greenish in color, and was 
nearly pure carbonate of lime. * 



* For details of this serpentine and its analysis, see Amer. Jour. Science, (2) xxvi., 263, and Geology of Canada, 
1863, p. 635. 
ee 
