= 
On Certain Cavities in Quartz, §. 139 
The solution from which the oxalate of lime had been thrown 
down was treated with ammonia and phosphate of soda, without 
having its transparency effected, whereby the absence of magne~- 
sia and lithia in the mineral was apparent. After several hours 
standing, chloride of platina was added, which immediately gave 
rise to the fine granular precipitate of the double salt of platino- 
chloride of potassium 
_ Whether the waa: contains eile as well as biden Iam not 
at present able to say. st 
The following tenefast isa sameey 6 what I have been 
able to infer respecting the chemical mamma of the mineral 
under consideration : : 
Silica, wines ey - - 56.00 
Lime, - - - °° 1» 2B88 
Alumina, - : hos - ‘L70 
Yttria?. : oe cng OSS 
Potassa <iiieks with so) oa ie. 5.12 
Water, — 8.00 
: 100. 
The above result favors the ida of the following atomic ar- 
rangement : viz. 
10 Ga see GS Al +5 ly iat 
Arr. XII.—On Certain Cavities in Quartz, &c., in a letter to 
the Editor, Foem d oe Wanaraton.t L. oe aa Bec Lancaster, 
- Penn., Dee. 9, 183 pa: 
_. Dear Sha = ERAS our —— and its vicinity I have — 
several anomalous specimens of quartz, 
of the different faces and. angles of crystals, that aia be- 
came detached. _ In most of these specimens these impressions 
are deep, giving a cellular aspect to the whole mass. In some, 
they are tabular and evidently rhombic, or portions of rhombs, 
having their various angles and. inclined faces accurately defined. 
In others, the indentations are principally pyramidal and cuneiform, 
with here and there a tabular rhombic impression. In one large 
and beautiful specimen, the cells are much larger, and more uni- 
