212 : [Senate 



from narrow rifts and veins of the rock, and a white incrustation, 

 found both here and at Hoboken, was long since ascertained by Dr. 

 Eruce of New-York, to be the hydrate of magnesia. (See Bruce's 

 Mineralog. Journal, page 26.) Crystals of chromate of iron are al- 

 so diffused through the rock, but not in sufficient quantities to be em- 

 ployed in the manufacture of chromic yellow, (or chromate of lead.) 



On the hills near the quarantine establishment, a great variety of 

 magnesian minerals may be obtained. The serpentine rock is laid bare 

 on the side hill near the road south of the Quarantine, and at its base, 

 in the road near the Black Horse tavern; also in the low ground south 

 of Richmond village, on the road by the Fresh Kills. Thus the whole 

 of the hilly part of the county appears to be underlaid with magne- 

 sian rock. 



The rocky portion, and some other parts of the island, are over- 

 laid with an upland diluvial formation of rocks, stones, gravel and 

 sand, covered with a stiff clayey soil. The surface rocks and stones 

 and detached boulders, are principally greenstone, evidently brought 

 here from a more northern region. iVmong them are some granite 

 and gneiss rocks, occasionally portions of graywack, and some pie- 

 ces of red sandstone. But the writer in all his walks and excursions, 

 has not seen a single specimen of serpentine, either on or under the 

 surface, except at places where the base rock crops out. The soil of 

 the island is therefore not a magnesian soil, but one derived from oth- 

 er sources than the base rock. The subsoil is in most places a hard 

 pan of clay, gravel and water worn stones and rocks, like those found 

 on the surface. The surface rocks are not so numerous as to furnish 

 materials for stonewalls, of which there are only a few in the county. 



On the north side of the island, near Port Richmond, a stone quar- 

 ry has been opened and is now worked, and the material sold in New- 

 York for granite. It is hard, and looks well when hammered into 

 blocks for masonry, arid may answer all the purposes of building; but 

 the rock is not granite, but a continuation of the greenstone formation of 

 the Pallisadoes on the Hudson river. It will be found on future ex- 

 plorations, that it is underlaid by sandstone, like the same formation 

 in New-Jersey, and the sandstone probably resting on serpentine, and 

 the serpentine on granite. The reddish soil at the base of the hill near 

 the Black Horse, is decomposed sandstone. Red sandstone has been 

 seen in the banks on the south side cf the island, and in a piece of 

 rising ground near Rossville, on the road from thence to Richmond. 



While most of the soil of the island is clayey, it is not entirely so. 

 New Dorp plain, in Southfield, is a sea alluvion of sand and gravel, 

 with a light loamy soil; the land in possession of able farmers, who 

 raise wheat and corn in abundance, and make large quantities of 

 hay. 



The soil in Westfield is partly clayey, but the west and southwest 

 portions of the township have a light and sandy soil, and in some pla- 

 ces it is reddish like that of New-Jersey, formed from disintegrated 

 sandstone. There are few large farms in those pai'ts of Westfield. 

 Most of the inhabitants own small tracts or mere garden spots, where 

 the light soil is adapted to melons, cucumbers and other vegetable 



