r, . TRANSACTIONS OF THE SECTIONS. 49 
wire, on cooling a small bubble of gas is formed, which is found to be mixed oxygen 
and hydrogen in the proportions in which they form water. This is the result of the 
first action of the heated wire: in a few seconds a small bubble of gas is formed ; 
but if the action be indefinitely continued, the gas does not increase in quantity. 
It is however easy to remove the bubble after it is formed, and bring a fresh supply 
of steam under the influence of the heated wire, and thus to collect a sufficient 
quantity of gas for an eudiometric examination. 
_ Numerous forms of apparatus were described by which this result can be ob- 
tained. It might be objected that, as the wire was ignited by a voltaic battery, the 
_ decomposition was not due to the heat of the wire, but to an electric action. This 
_ objection would not indeed be maintained by those who were well acquainted with 
electrical phenomena. With the view, however, of removing all doubt, the use of 
_ the battery was entirely done away with, and all the results obtained by the agency 
' of heat alone, in the following manner :— 
Into a silyer tube a narrow tube of platina is soldered ; and this is again connected 
_ with a bent tube which admits of the removal of any gas formed. The tubes being 
filled with distilled water, and the open extremity immersed in a vessel of water, the 
_ flame of an oxyhydrogen blowpipe is made to act upon the narrow tube of platina, 
by which this is brought to a white heat. The water is of course instantly con- 
verted into steam, and this steam is decomposed by the agency of the heat alone. 
By apparent boiling, we thus convert steam into mixed oxygen and hydrogen gases ; 
and this operation may be continued for any length of time by bringing a fresh 
_ supply of steam under the influence of the ignited platina. Ifa fused or intensely- 
| heated globule of platina is plunged into water, bubbles of oxyhydrogen gas imme- 
| diately ascend from it, which may be collected in an inverted tube. 
Prof. Grove went on to show the probable connexion between this phenomenon 
of decomposition, and the spheroidal state of fluids when projected on capsules of 
| heated platina; this had been referred to a repulsive action of a coating of steam 
_ enveloping the spheroid of fluid; but in all probability the spheroidal drop was 
_ made to assume a state of tension approaching decomposition by the agency of the 
_ heat to which it was exposed. He also entered into several considerations suggested 
_ by the above facts as to the relation of heat to chemical affinity, as well as their 
geological bearings and possible practical applications. 
Notice of a Gas Furnace for Organic Analysis. By Joun Percy, M.D. 
In this arrangement, gas burnt, mixed with air through wire-gauze, is substituted 
for charcoal. The advantages are its extreme cleanliness, and the power which the 
operator possesses of regulating at will the heat, which is not practicable in the or- 
dinary furnace for organic analysis with charcoal. 
Extraordinary appearance in the Flame of a common mould candle. 
By E. R. J. KNow es. 
The writer’s attention was suddenly attracted by the light of the candle flitting, 
as though a moth had flown into the flame, when to his surprise instead of an insect 
struggling he saw a bright spot revolving with great rapidity in the flame; on exa- 
“mining it, the bright spot was found to be the end of a very fine filament attached to 
the side of the wick about half-way up the ignited part, and thus held to it, while 
_ the extremity with the bright spot of light revolved in a circle like a ‘‘ Catherine 
_wheel,””—the circle described being about 4th or 33,ths of an inch in diameter. It 
moved with a velocity of about three or four revolutions in a second, and ceased 
revolving in about three seconds. As stated, when it commenced it was a very small 
- luminous point, and it increased visibly in size as it revolved, becoming eventually a 
ball or aggregation of carbon, suspended by a single thread like a very fine hair. 
| Experiments on the Expansion of Salts. By Messrs. Joure and PLAYFAIR. 
[This paper will be published elsewhere in extenso. ] 
1846. E 
