144 Proceedings of Societies. 
also made to the remarkable series of greenstone and basalt dykes 
which traverse Scotland from N.W. to S.E., and enter the northern 
English counties. From observations made at either end of the 
series, the author deduced the inference that these dykes are later 
than the Lias, and probably belong to the period of the Middle or 
Upper Oolite. 
2. Notes on Ancient Glaciers made during a brief Visit to 
Chamouni and its neighbourhood in September 1860. 
By David Milne-Home, Esq. of Wedderburn. 
(This paper appears in the present number of this Journal.) 
Monday, 29th April 1861.—Proresson ANDERSON, 
in the Chair. 
The following Communications were read :— 
1. On the Aqueous Origin of Granite. By Alexander Bryson, 
P.R.S.8.A. 
In this paper the author referred to the labours of Dr William 
Smith, who published his ‘‘ Tabular View of the British Strata” in 
1790, and remarked that since that period geology had been studied 
mainly in the direction of Paleontology. Physical, chemical, and 
dynamic geology, were left almost unregarded by the great masters 
of the science, who generally accepted the speculations of Hutton 
and the experiments of Hall, as demonstrating the igneous origin of 
the primary rocks, 
The author stated that the Huttonian theory was most ably 
attacked, and, in his opinion, overthrown by Dr Murray in his 
“ Comparative View of the Huttenian and Neptunian Systems of 
Geology,” a work most unaccountably overlooked. Since that time 
it had suggested itself to the sagacious mind of Davy, that the 
occurrence of fluids in the cavities of crystals seemed to point to an — 
aqueous origin. He also alluded to the writings of Brewster, Sive- 
wright, and Nicol, in the same field; also to Becquerel, Fuchs, 
Bischoff, and Delesse, who have taken up the subject of the aqueous 
origin of rocks from a chemical point of view. The author then 
laid before the Society the result of ten years’ experimental investi- 
gation into the structure of rocks relative to their formation, more 
particularly granite. While examining microscopically the various: 
pitchstone veins abounding in Arran, he was much struck with the 
similarity of their structure, and the marked difference they ex- 
hibited when compared with sections of granite and its various 
