The British Association . 
543 
1878.3 
must have equalled probably two hundred times the entire 
volume of the present atmosphere of our earth. This 
amount could not, of course, exist at any one time in the 
air ; it would at ordinary temperatures be liquefied at the 
earth’s surface. Whence came this vast quantity of car- 
bonic acid which must have been supplied through the ages ? 
The hypothesis of Elie de Beaumont, who supposed a reser- 
voir of carbonic acid stored up in the liquid interior of the 
planet, was discussed and dismissed. The gas now evolved 
from the earth’s crust from volcanic and other vents was 
probably of secondary origin, and due to carbonates previ- 
ously formed at the surface. The solution of the problem 
offered by the author is based upon the conception that our 
atmosphere is not terrestrial, but cosmical, being a universal 
medium diffused throughout all space, but condensed around 
the various centres of attraction in amounts proportioned to 
their mass and temperature, the waters of ocean themselves 
belonging to this universal atmosphere. Such being the 
case, any change in the atmospheric envelope of any globe, 
whether by the absorption or the disengagement of any gas 
or vapour, would by the laws of diffusion and static equili- 
brium be felt everywhere throughout the universe, and the 
fixation of carbon at the surface of our planet would not 
only bring in a supply of this gas from the worlds beyond, 
but, by reducing the total amount of it in the universal at- 
mosphere, diminish the barometric pressure at the surface of 
our own and of all other worlds. 
Prof. W. King, D.S.L., contributed a paper 11 On the Age 
of the Crystalline Rocks of the County Donegal.” He had 
succeeded in obtaining some true fossils in portions of the 
Innes Lower Limestone that have scarcely undergone any 
change. This was the first example, as far as he could as- 
certain, of an undoubted fossil having been detected in these 
limestones. The faCt may be taken as evidence that their 
deposits and their associated argillaceous and siliceous 
masses are of the Lower Silurian Age, and it seemed highly 
probable that the more intensely metamorphosed rocks in 
the north-west division of Donegal belonged to the same 
geological period. 
Biology. (Section D.) 
The President of this SeCtion was Prof. Flower, F.R.S.; 
Dr. Robert M'Donnell, F.R.S., presiding over the Depart- 
ment of Anatomy and Physiology, and Prof. Huxley over 
that of Anthropology. Our space will not permit us to give 
abstracts of the excellent addresses of these gentlemen, or 
of the papers brought before the SeCtion, 
