50 REPORT—1874. 
and the nature of the forces acting upon them. Whence can we look for such 
knowledge ? 
The phenomena of gaseous diffusion, of gaseous friction, and of the propagation 
of heat through gases have already given us an approximation to the size and mass 
of the molecules of gases. It is not unreasonable to suppose that a comparative 
study of the specific heat of gases and vapours may lead to some approximate 
knowledge as to the shape of their molecules ; and a comparison of such approximate 
results with the chemical constitution of the substances may lead to an hypothesis 
which will lay the foundation of a real theory of Chemistry. 
Chemistry will then become a branch of applied Mathematics ; but it will not 
cease to be an experimental science. Mathematics may enable us retrospectively to 
justify results obtained by experiment, may point out useful lines of research, and 
even sometimes predict entirely novel discoveries, but will not revolutionize our 
laboratories. Mathematical will not replace Chemical analysis. 
We do not know when the change will tale place, or whether it will be gradual 
or sudden ; but no one who believes in the progress of human knowledge and in the 
consistency of Nature can doubt that ultimately the theory of Chemistry and of all 
other physical sciences will be absorbed into the one theory of Dynamics. 
On the Composition of an Inflammable Gas issuing from below the Silt-bed in 
Belfast. By Dr, Anprews, [.2.S. 
In sinking for a well upon the premises of Messrs. Cantrell and Cochrane, in 
George’s Lane, Police Square, Belfast, after having passed through a deposit of 
silt to the depth of 33 feet, a layer of gravel was reached, 7 feet in thickness, 
and containing a quantity of organic débris. It rested upon a thick deposit of very 
tenacious clay. On entering the gravel-bed, a large flow of water occurred, which 
rose to within 4 feet of the surface of the ground, and interrupted the operation of 
boring, till a pump, worked by a small steam-engine, was erected, which, so long 
as it was in action, kept the boring free from water as far as the surface of the 
gravel-bed. A workman, having lowered a light to examine the bottom of the 
well, was surprised to see a lambent flame playing over the surface. On examina- 
tion this was found to arise from a disengagement of inflammable gas, which had 
accumulated between the lower surface of the bed of silt and the layer of gravel. 
An iron pipe, terminating in a funnel-shaped mouth, about one foot in diameter, 
was now sunk till it reached the gas-stratum ; and the water in the well was kept 
by pumping at such a level that an extra pressure of about one inch of water was 
maintained upon the gas below. The gas now flowed freely, at the rate of about 
40 cubic inches per minute, through the upper end of the iron pipe, and, when 
ignited, burned with a yellow flame, which could scarcely be distinguished from 
that of ordinary coal-gas. 
Two portions of the gas were carefully collected by displacement, the stream of 
gas being allowed to pass till the whole of the atmospheric air in the vessels was 
completely swept away. The connecting tubes were then carefully sealed, and the 
pas was afterwards analyzed in the laboratory of Queen’s College. 
A measured volume of the gas, standing over mercury, was exposed to the action, 
first, of caustic potash, and afterwards of pyrogallic acid, and the residual gas was 
afterwards analyzed with the following results :— 
Vv. TT | B. C. 
Atmospheric air ............65 78:7 12:2 7706 308°8 
After addition of residual gas....} 1205 12:4 7715 2722 
After addition of oxygen........ 190:0 12:8 771°8 221°8 
Ater CON. ese Teneo s te yc 1265 13:0 7717 271°6 
After action of potash.......... 90:0 11°8 7720 299°7 
