238 
TaBLE 1V.—Jsolated Granites. 
Perox- so) y Logs 
LocaLity. Silica. Zit ide of | Lime. bee it be) Soda. by Je ToTat. 
1.Cushbawn,. . .| 70°32 | 11-24 | 4:80 | 3°01| 0°73| 2:27 | 3-39] 1-62} 97-36 
2. Croghan Kinshela} 80-24 | 13-24 | 0:72 | 0°89 |Trace| 0°40 | 5-58} — |101-07 
3. Ballymoty,. . .| 66°60 | 13-26 | 7-32 | 3°36] 1:22 | 2°31) 3:60 | 2°34 1100-01 
4, Ballynamuddagh, | 68-56 | 14-44 | 5:04 | 3°85 | 0:43 | 2°78 | 3:36| 1-00] 99-46 
“No. 1. Cushbawn.— Specific gravity, 2°671; a fine- 
grained granite, containing hornblende in addition to mica. 
Besides the constituents given in the Table, the specimen ex- 
amined by me contained 1°34 per cent. of carbonate of lime. 
“‘ No. 2. Croghan Kinsheia.—Specific gravity, 2-629 ; this 
granite is composed of quartz, feldspar, and chlorite. The 
specimen examined appeared to be composed exclusively of 
quartz and feldspar. From the great quantity of soda, I infer 
that the feldspar of Croghan Kinshela is probably albite. On 
the northern slope of this mountain are situated the old gold 
streams of Wicklow. 
“No.3. Ballymotymore.-- Specific gravity, 2-659; a very 
fine-grained granite, but containing distinctly feldspar, quartz, 
and black mica. 
‘©No. 4. Ballynamuddagh.— Specific gravity, 2:670; a 
coarse-grained granite, with large plates of black mica. 
‘* Applying to the preceding granites the method of calcu- 
lation already employed, we find, excluding the granite from 
Croghan Kinshela, which contains chlorite in place of mica—- 
TasLeE V.—Atoms of Granitic Minerals. 
Atoms | Atoms |Atomsof] Atoms | Atoms | Atoms 
Loca.ity. of Silex jof Perox-| Protox- of of Feld- of 
=a. |ide =b.|ide =c.| Quartz.| spar. Mica. 
Cushbawn, . . .| 1529] 0-278} 0300) — — — 
Ballymoty,. . .| 1448 | 0°349 | 0°346 | 0-067 | 0-343 | 0-003 
Ballynamuddagh, | 1°490 | 0-344 | 0-325 | 0:209 | 0°306 | 0-019 
