174 On the Connexion between the [Sepr. 
motions the flame of the gas issuing into the mine from the first 
pore touched the gas from an adjoining pore, and set it on fire, 
which did so with the gas from a third pore, and thus the motion 
of the flame continued ; but as the gas issues from every pore at 
intervals, the portion set on fire at the first pore was consumed 
before another issued from it, but not before it inflamed the portion 
of gas then escaping from the second pore, which, though con- 
sumed before another portion left that pore, communicated with 
the gas of a third pore, and so on. In this manner the flame’s 
flitting motion was produced. When the gas escapes from the 
pores of the coal in constant streams, or at least in a succession of 
portions at very smail intervals, the flame is stationary at every 
ore. 
With the help of these remarks, we may make the following 
conclusions as to the origin of the carbureted hydrogen gas of coal- 
‘mines. It isa part of the matter of the coaly strata; but how it is 
separated we cannot exactly determine. It may be set at liberty by 
the action of the component parts of the coal on one another; but 
not in the way of decomposition by fermentation. Or it may con- 
sist of an original redundancy of volatile matter which has been 
kept in by pressure, but which, as soon as hollows are made into 
the coal, is suffered to escape. The gas, by either mode of forma- 
tion, may very well exist in the rents above the coal: for as these 
rents were forming, room was made for the gas to lodge in; and, 
to account for its degree of compression, we know that it afterwards 
escapes from the coal with a great force, and, if suffered to fill 
hollows like these rents, would leave them with a similar velocity. 
: Artic.e III. 
On the Connexion between the Vascular and Extra Vascular Parts 
of Animals. By Anthony Carlisle, Esq. F.R.S. 
(To Dr. Thomson.) ‘ 
SIR, Soho square, July 3, 1815. 
Tue following memoir having been partially made known to the 
public, I beg you to lay it before your scientific readers, as a means 
of preventing misrepresentation or piracy. 
Sir, your obedient servant, 
AntTHony CARLISLE. 
General or comparative anatomy, the great branch of natural 
knowledge on which the rationale of the medical art is founded, has 
lately risen in esteem, and is every day more accurately and more 
extensively cultivated. Considering how intimately the discovery of 
new facts, their relation to each other, and the physiological in- 
