The Rev. S. Haughton’s Notes on Mineralogy. AT 
These operations being performed, gave 
Vis ive Us Gy cis B. -Y. 
(W) + 7014+2282+41060—1474—3641 + 1072=0. 
(Y) +42863—2761 + 1235+41131+ 299—2767=0. 
From these were obtained the following results by elimina- 
tion :— 
TaBLe V. 
Ww B 
Equation v. U. G. i . Y. 
I From(W)and(Y) O —54:1 —13'9 +320 +68:0 —32:0 
* | From observation 0 —54°7 —13°5 +321 +679 —31'8 
ll { From (W) and(Y) —59'6 0 —40'4 +104 +66:0 +23°6 
* | From observation —60°2 0 —39'8 + 9:2 +682 +22°6 
ll Pah dconaias —21°7 +57°4 0 —30'2 —481 +42°6 
* ‘| From observation —21°5 +56°8 0 —29°3 —49°2 +43°2 
IV ae eel ean ote +186 —37°6 0 +45°7 +357 
* ‘| From observation —62°7 +17'°2 —37'3 0 +485 +343 
Vv ule Be +556 —490 +252 +192 0 —51:0 
* | From observation +55°7 —48°7 +261 +4182 0 —51°3 
VI From (W) and (Y) —39°7 —26°6 —33°7 +22°7 +773 0 
‘ ee observation —38'8 —27°2 —34:0 +283 +762 0 
JAMES CLERK MAxweELL. 
Glenlair, June 13, 1857. 
V. Notes on Mineralogy.—No. VI. On the Siliceo-Felspathic 
Rocks of the South of Ireland. By the Rev. SaMuEL 
Haveuton, M.A., Fellow of Trinity College, and Professor of 
Geology in the University of Dublin. 
T is well known that siliceo-felspathic trap rocks of a pecu- 
liar kind are found in the mining district of the Ovoca, 
Co. Wicklow, and in the mining district of Bonmahon, in the 
south of the county of Waterford; and the recent investigations 
of the Geological Survey in the west of Kerry and Cork have 
brought to light the existence of great quantities of similar rocks 
in the neighbourhood of Killarney, and in the mountains to the 
westward stretching to the south of Kenmare Bay; and it is 
not at all improbable but that these remarkable felspathic rocks 
may in this district be associated with the copper lodes, which 
have proved so productive in the Berehaven or Allihies Mine. 
These rocks have a general resemblance to each other in all these 
districts, and when once seen and recognized cannot be easily 
* Communicated by the Author, 
