20 On the Serpentine Rocks of Hoboken, N. J. &. 
ging clusters, of a pale green or greenish-grey colour and 
a pearly submetallic lustre, soft enough to be easily cut by 
a knife, and almost perfectly opaque, inflexible, and brittle. 
Its poyder is unctuous and shining. By the influence of 
the weather it becomes whitish and more brittle. Its spe- 
cific gravity by Nicholson’s balance was 2,470. 
Chemical characters. Before the blowpipe it decrepitates, 
hardens, and slightly exfoliates without showing any sign of 
fusion. 
100 grains after an hour’s ignition lost 15 per cent. and 
the fragments were then sufficiently hard to scratch glass. 
The remaining 85 grains were dissolved in nitric acid and 
formed a thick and partly gelatinous mass. After the so- 
lution appeared complete, there remained on filtration and 
desiccation by ignition 35 grains of silex, which with pot- 
ash readily fused with effervesence into a pellucid glass. 
The metallic matter was then precipitated by prussiate 
of potash and by the grass green colour of the solution ap- 
peared mixed with a minute portion of chrome. This pre- 
cipitate of a deep blue amounted when dried, after making 
the necessary reduction, to one half a grain of the protoxid 
of iron. 
Concentrating the solution to dryness and lixiviating, there 
remained one grain more of silex. 
‘The earth previously ascertained to be principally mag- 
nesian, was now precipitated by caustic potash, and the 
precipitate boiled to separate the alumine it might con- 
tain. 
The alkaline liquor was again supersaturated with muri- 
atic acid, to which ammonia was added, but without produ- 
cing any precipitation. 
The precipitate by caustic potash, after edulcoration and 
ignition, sufficient to expel the carbonic acid, weighed 46 
grains, and was then redissolved in sulphuric acid, which 
after repeated digestion and solution, deposited five and a 
half grains of gypsum, equivalent to two grains of lime. 
