Professor Dcebereiner's recent Discovery , to Eudwmetry. Ill 
the balls No. 1. and 2. into the others, all being cold : no imme- 
diate action ensued, and the diminution after twelve hours was 
very slight ; traces of carbonic acid were discoverable by lime-wa- 
ter, which shows that some chemical change had been occasioned. 
The experiment was repeated, with this difference only, that the 
mixtures were heated to near the boiling point of mercury. 
The diminution was now greater than before, and more carbo- 
nic acid had formed, but the residue was still explosive. 
Coal-gas and hydrogen were mixed in various proportions, 
and to each mixture sufficient oxygen was added for complete 
combustion. 
When the coal-gas was to the hydrogen as 3 : 1, No. 2. had no 
immediate action, at common temperatures ; but if ignited be- 
fore the blowpipe, and then plunged rapidly into the mixture, 
just after it had ceased to be red, an immediate diminution of 
volume followed, and the ball became luminous. 
When the coal-gas and hydrogen were as 2 : 1, the ball No. 2. 
acted precisely as in the preceding experiment. The same oc- 
curred when the gases were as 3 : 2. When they were in the 
proportion of 2 : 3, and the ball was heated so as just to be borne 
on the hand, a rapid diminution of volume succeeded, without 
.emission of light. The ball likewise acted, though with far less 
energy, when cold. 
When the coal-gas and hydrogen were as 1:2 , the ball act- 
ed nearly in the same manner as before, though with more 
energy. 
In all these experiments there was copious production of car- 
bonic acid, but the residue still contained an explosive mixture. 
The coal-gas, as obtained from the pipes, always contains some 
carbonic acid, which, of course, was previously removed by po- 
tash. 
Olefiant gas, carefully prepared and well dried, was mixed 
with three times its volume of oxygen. Spongy platinum, as 
well as the balls, had hardly any action upon this mixture, when 
cold or gently warm. Heated to near the boiling point of 
mercury, a partial action succeeded, with production of carbonic 
acid. A platinum ball was heated to vivid redness before the 
blowpipe, and then introduced quickly into the mixture ; it act- 
ed with energy, for there was on the instant a copious produc- 
