\ 
Newly discovered Meteoric Tron, Al7 
(water being 1-000), giving a mean » which, with 
the formula fixed by Anderson, Cs6H21N Os+H202=3817, gives a 
lume of 244. The density was determined in distilled water, and I 
convinced myself that the loss by the slight solubility of codeine in this 
liquid, produced no sensible error. 
_Thave made two determinations of the density of transparent cleava- 
ble rock salt, in oil of turpentine, and h&ve obtained the numbers 2°137 
and 2-134, (water being 1-000,) which approach very nearly to that of 
Kopp, 2-15. Taking as the mean 2-135, we have for the volume 
10NaCl the number 172, corresponding to the volume of alum, 274. 
is Journal [2], vol. xvi, p. 2 
| 
uous slates, which disintegrate very much by the action of the 
Weather, and have hitherto been known by the name of talcose slates. 
afforded me the composition of pholerite. I shall send you soon my 
detailed results ; meanwhile, to avoid the perpetuation of an error, I 
would suggest for these unctuous aluminous schists the name of nacre- 
ous or nacrite slates. eae 
lined with a film of oxyd. It el ly resembles in appearance the 
rt (IN. Y.) iron, with which it seems to agree in composition; @ 
single analysis gave me per cent of nickel, in which 
q  *Prears to be the arseniuret of copper, since the varying results of sey- 
§ eral analyses, dutaapiedis to different mixtures of the two species. As- 
Sociated with these is an amorphous earthy mineral with a conchoidal 
Szconp Sznres, Vol, XIX, No. 57.—May, 1855. 
