Miscellanies. 173 
Atoms. 
Silica, ‘ 19.35 s 9.68 
Alumina, . 44.75 ‘ 19.88 
Zirconia, ‘ 2.05 " 0.54 
Perox. iron, 4 4.80 4 0.96 
Ox. manganese, . 1.35 ° 0.30 
Lime, , 11.45 ‘ 3.27 
Magnesia, : 9.05 , 3.62 
Water, ; 4.55 ’ 4.04 
Fluoric acid, ‘ 0.90 =. 0.72 
Supposing the fluoric acid to be united with lime, and to consti- 
tute fluor spar, = constitution of the mineral is thus expressed : 
11A13S+ f “(a5 1$Cal 3S + 2Mag 3S + 2Aq 
The mineral is asia in honor of Dr. Holmes, Prof. of Chem- 
istry in the McGill College of Montreal. 
2. Compact Feldspar, from Bytown, Lower Canada. Sp. gr. 
2.8617. 
Silica, ‘ , F ‘ 45.80 
Alumina, é 26.15 
Perox. iron, 4.70 
Lime, 16.25 
Magnesia, . . ‘ 2.95 
Water, ‘ : ‘ : 2.00 
97.85 
Cal 
Its formula is 2A] S+ Mg +S? 
According to Dr. Tuomson, it is identical with Amphodelite, 
which he considers a variety of Scapolite. The formula of Scapo- 
lite is 2AIS+CalS. 
3. Deweylite * = gr. 2.0964. 
Silica, ‘ , 50.70 
Magnesia, . , . ‘ 23.65 
Water, ‘ . . , 20.60 ° 
Alumina, . ; ; 5 3.55 
Protox. iron, . . ‘ ‘ 1.70 
. * The locality of this mineral is not known. 
