270 
that the pressure at the bottom of the well, which is not 
tubed, is much greater, as it lifts a column of water not less 
than 500 feet in length. 
SOURCE OF THE GAS. 
All the gas wells on the Lake shore draw their gas from 
some point above the Huron Shales. A great mass of bitu- 
minous strata, the equivalent of the Genessee and Cashaqua 
shales of New York. This bituminous formation underlies 
the oil region of Western Pennsylvania, and all the oil and 
gas belt of Ohio. Many wells have been carried through this 
formation, but in no case upon the Lake shore, has gas been 
obtained below it. For this and other reasons that might be 
advanced, I think we are justified in concluding that the gas 
and the oil of the region under consideration are derived by 
spontaneous distillation from the bituminous shales to which 
reference has been made. 
October 23d, 1871. 
The President in the chair. Seventeen persons present. 
Mr. R. Dinwippre announced the Death of Sir Roderick 
Impey Murchison, one of the Honorary Members of the Society, 
and exhibited a photograph of the deceased. 
Mr. R. H. BrownnzE exhibited a Necklace of Cut Amethysts, 
from Oberstein, Germany. 
Pror. T. E@Leston made some remarks on the Artificial 
Coloration of Agates. 
It is not generally known that most of the Agates 
which are used for ornament, are artificially colored. This 
art of coloring natural stones, is carried on on an immense 
scale at Oberstein in Germany, where the greater part of the 
Agates of Europe are cut. Most of the Agates which are cut 
there come from Brazil. Those which are naturally colored are 
generally different shades of red. Ifthe color is of the desired 
shade they are immediately cut, but if not, or if the shade of 
. 
