ON THE CONSTITUTION OF THE GRANITES OF DONEGAL, 59 
Of these a great number are of minor importance, and only a few have been 
analyzed, in consequence of the difficulty of obtaining them in a sufficiently 
pure state for that purpose. This has been the case with the sphene and the 
scapolite. Allusion has been made to the frequency with which potstone and 
soapstone are met with in the county, and we have therefore considered it to 
be of interest to analyze both it and the silky crystals which are found in it, 
especially at Crohy Head. 
No. I, No, I. 
Crystals, Massive 
soapstone. 
STUER, Ateie excocarae ne ae aE a Ni GaSa th: Pe ae 60°24. 
PAV TUTTI Pete al dane apie ina.sa a pi3 ORs ct BO aaeRr es 1-12 
Hiren (VerORIde) ..-..0-.... it, ee ta prea 1-48 
Bae R CG es 5 et ugaleateay > PEACR., vrinevelting een trace 
Line Siete ee ee eee meet TPO CO a ee a cus 0:00 
(FET Ea ee EOS 6 iia gate bein 35°14 
Sera) 5 ee et RRP Po eG ae tte Te 5 0-41 
MRED ee f8 scl ss 2m fn up taas daflans E01 RP er kee 0-07 
WROD iis as so, st rsce eh 36.0 OAD we eo ter ores ths 1-00 
99°53 99-46 
From these analyses it will be seen that the mineral is a true anhydrous 
tale; and this fact is the more interesting inasmuch as we can trace, both at 
Gartan Abbey and at Crohy, the gradual passage of this mineral into antho- 
phyllite, with the crystalline form of which mineral the radiated silky crystals 
of that under examination are evidently closely connected, 
* Rammelsberg does not include among his analyses of the hornblende family 
any which is absolutely free from lime, although Scheerer’s analysis of the 
asbestus from St. Gotthardt (Mineralchemie, p. 475, No. 7) is nearly so, and 
this mineral accompanies tremolite. On the other hand, the presence of the 
Taste V,—Chemical Composition of Donegal Granites. 
o 
é | 3] 8 SE 
0. 3| # g So B| # 7 
% 2/2 leet e/a] 4/4/28) 2) 4 
= eSlPelS i318) 8 isk g 
oi S4 Fea Bla lala BBE] a 
I. Ardmalin .,,.,.,,./70°00 |16°36 |2°80 |0-08 |1:12 \0°71 |4°13 |4°66] ... | ... | 99°86 
II. Urrismenagh...... 65°80 |12°80 |6°64 |0°18 |2-92 |1°78 |4°16 |4°40| .,. |1:20| 99°88 
MA GIEN, aececisp ales 68°96 |17°40 |2°52| ... 12°80 |0°41 13:08 15°25} ... | ... 1100-37 
TV. Glen’. ....6.5ii a 58:44 |20°00 |6:44 |2°05 |4-'72 |1°57 13°81 12°82 | ... |... | 99°85 
V. Glenveagh......... 69°36 |16-00 |3'03 |0°80 |2°29 |0°54 |4°17 |4°47| ... | ... |100°16 
VI. Glenveagh......... 68:00 |16°80 |3°68 |0°65 |4°05 |0°95 |4°32 |2°04] ... | ... |100°49 
VII. Poison Glen ...... 68:20 |15°96 |3°69 |1:00 |2°92 |0°78 |3°75 |4°14| .., |... |100°44 
VIII. Poison Glen ...... 70°64 |15°64 |2°64.| ... |2°4°7 (0°15 [3°81 |4°53) ... |... | 99°88 
IX. Doocharry Bridge 72°24 |14°92 |1°63 |0°23 |1°68 |0°36 |3°51 [5:10 |0°32| ... | 99°99 
X. Barnesmore ...... 73°60 |18°80 |2°00| ... |0:79 |0°50 |4-29 |5°22| ... | ... |100°20 
XI. Arranmore........: 68°80 |16°40 |2°60 |0°65 |1°75 |0°85 |3°78 |5°31|] ... | ... |100°14 
XII. Tory Island ...... 69°20.|16°40 |2:09 |1:00 |1:03 |0°85 |4°20 |5°22] ... | ... | 99°99 
XIII. Ardara ............ 55°20 |19°28 |6:08 |0°46 |5-08 |3°66 |4-63 |3°17 |0-96 |0°64| 99°16 
XIV. Dunlewy ........... 75°24 |13°36 10°60] ... |2°25 |0°14 |4°86 |3-27] ... | ... |-99:72 
XV. Annagary ......... 73-04.|15-20| ... | ... [1:60 |0-07 |2°88 |7:82| ... | ... {100-12 
XVI. Strontian........... 62:09 |1'7-60 |4-'78 |0:'74 14°95 |3°17 |4°08 13°25 |0-40} ... |101:06 
XVII. Tobermory, Mull (70°60 16°40 {1°52 |0°36 |2°47 |1°00 |4°14 |4°29 |0'48| ... |101-26 
a 
