278 Reports and Proceedings. 
life. In conclusion, Mr. Bryson remarked, as a curious circumstance, 
that the advocates of the upheaval theory have never sought for con- 
firmation of it on the rocky shores of the many islands of the Firth. 
2. Mr. James W. YouneG read a paper On the Presence of Magnesia 
in Rocks.—After some remarks on the occurrence and distribution of 
magnesia and carbonate of magnesia in the crust of the earth, he said 
that he had been for some time past engaged in examining some of the 
local limestones, and found that there are very few which do not con- 
tain at least considerable traces of it. In Campsie, Ballagan, and 
Auchenreoch Glens, and at Loch Thom, Renfrewshire, a formation 
occurs, known as the ‘ Ballagan Beds.’ They consist principally of 
thin layers of limestone, alternating with beds of a bluish-grey shale. 
A few remains of Plants and scales of Fishes have been found in a 
sandstone of the group. They are considered to be the lowest beds 
of the Carboniferous formation. The following table gives the 
result of the analysis of the limestones from the various localities. 
The general composition of the whole of them is similar to that of 
No.1. They are of various shades of grey, are compact and amorphous, 
streak white. ‘The colour is owing partly to protoxide of iron, and 
partly to organic matter. Where exposed to the air, a reddish tinge 
is produced, owing to the peroxidation of the iron. 
1 2 3 4 5 6 
Sp. Gr. at 15°°5 C. — — 277 2-75 — — 
Insoluble ppcipally Clay and 
Sand lie?) 25:1 12°48 | 17°88 | 11:48 6°44 
Alumina 3 . 1°84 ochnted 
Proteendelo® iron tae EP TOE I Repeat nll Mae a ies 
Lime . : ‘A 3 . | 30°24 | 23:06 | 26°96 | 25°31 | 42°30 | 30°00 
Magnesia . : : - | 11°49 | 13°36 | 16°64 | 14°76 516 | 18°36 
Carbonie Acid. : 5 . | 34:50 = — = — — 
99-57 | — a ro aoe wid 
No. 1, from Campsie Glen, Stirlingshire. 
1 
» 2, ,, Gartshake Glen, Dumbartonshire. 
8, ,, Loch Thom, Renfrewshire. 
» 4, ,, Ballagan Glen, eee 
5 
Fs Pe 4 A red variety ; effervesced freely with 
dilute hydrochloric acid ; "in the grey limestones the effervescence was 
somewhat feeble. 
», 6. Limestone under trap, Shields’ Burn, Campsie. 
Another limestone, of Old Red Sandstone age, which occurs at 
Balgair Moor, Fintry, contains a large proportion of carbonate of 
magnesia. 
~ 
1 2 
Carbonate of Lime . a , 3 3 53:20 54:18 
Carbonate of Magnesia . 3 : : 44-00 45°82 
Insoluble . , s F ; 2°36 — 
Alumina, with trace of iron , i : 0-60 — 
100716 100-00 
