Native Crystallized Curbonaie of Magnesia. 148 
nesia in examining the strata exhibited in an excavation now 
making, under the delusive expectation of finding gold, about 
three miles from the Quarantine. In descending the shaft, 
sunk perpendicularly in steatite, magnesite, veins of talc, and 
green translucent asbestus were observed at depths from six 
to thirty-five feet. The magnesite was found to embrace veins 
and cavities containing native carbonate of magnesia, in very 
white acicular crystals, grouped in minute fibres radiating from 
the sides, but not always filling the veins and cavities. The 
crystals were, in some instances, suspended, assuming a sta- 
lactical form. This carbonate of magnesia dissolves entirely 
in diluted sulphuric acid, with considerable effervescence and 
chemical action, producing a bitter compound, from which salts 
of easy solution are formed by evaporation. ‘The magnesite in 
Which these crystals are found, appears to be composed of car- 
bonate of magnesia, steatite, and talc, disintegrating readily 
"pon exposure to air and moisture : it effervesces considerably 
in sulphuric acid, forming a very bitter fluid that soon exhi- 
bits crystals, indicating that magnesia enters in large propor- 
Hon into its constitution. Magnesite may perhaps be found at 
this place in quantity sufficient for a successful manufacture of 
Epsom salts, Small regular hexaedral crystals of mica, were 
Noticed in. steatite. Chromate of iron was sparingly diffused 
rough the different minerals raised from various depths. 
A few remarks and facts respecting the geology and minera- 
logy of Staten-Island, may, perhaps, give some additional in- 
terest to the Specimens presented. 
Staten-Island (which constitutes Richmond county) is situa- 
about seven miles south-west of the city of New-York, 
extends from north-east to south-west about fifteen miles, in a 
Straight line, with an average width of six. It exhibits a con- 
siderable diversity of surface. ‘The eastern part is composed 
Principally of elevated ground: a mountain chain is observed 
* © its rise in the vicinity of a narrow sound called the 
Kills, and Sweep, in a semicircular form, near the eastern 
shore; it then ranges south-west, parallel with, and distant 
trom Amboy Bay, about two miles, terminating near the centre 
of the island, and forming, with the exception of some passages, 2 
