On the Serpentine Rocks of Hoboken, N. J. &c. 19 
Nemalite, or Aiianthoid Magnesite. 
This substance, which forms veins in the serpentine of 
Hoboken, is in all probability one of the most deceptive min- 
erals ever discovered, since it appears in every respect as ‘a 
well characterized variety of amianthus for which it had al- 
en mistaken. It possesses the usual silky lustre 
and flexible fibrous texture, and is commonly of a pale blue 
colour. It cannot indeed like the genuine amianthus be re- 
duced to a flocculent mass, so as to be twisted and spun, 
and the a when presented to the flame of a lamp, in- 
stead of running up into a globule, like that of Massachu- 
setts, remain infusible, become 2 friable, opaque and rigid, 
time assume ht brown from the oxi- 
perenne Sea Seber 
in Seid ‘without efferreseh ce, ex escape jin such 
Rpanirs as have been exposed to the weather, or which 
are slightly contaminated nore carbonate of lime. Its spe- 
cific gravity I found to be 2 
y exposure to a sata heat, in the experiment 
which I made it lost 30 per cent. and in sulphuric acid was 
all converted into a well characterised epsom salt, exce 
about a grain of lime anda pene ne eee 
about 5 per cent. of the protoxide. 
This mineral when rubbed with a piece of i iron as well as 
the lamellated magnesite phosphoresces with a a yellowish 
hight. 
Marmolite. 
This mineral, which has latherto. ‘peed ceaidered'in this 
country as a variety of talc, forms also narrow veins in the 
pentine of Hoboken, and in that of the Bae leneer 
magnesian mar 
Its texture is foliated with shee: Sanita Ahiing one often 
Hel as in ¢ Sometimes also cleaving in two di- 
rections parallel to the sides of an oblique and rb ge 
four sided prism. These lamina, sometimes a quarter of an 
inch broad, are commonly collected into into radiating or diver- 
