Prof, Dcebereiner's recent Discovery , to Eudiometry. 105 
The ball No. 2., gently warmed, was put into 186 volumes of 
the same mixture, containing of course 1.86 hydrogen. In three 
quarters of an hour there was a diminution of 2.8, which indi- 
cates the presence of exactly 1.86 hydrogen. 
No. 2. gently warmed, was put into 132 volumes of the same 
mixture, containing 1.3 volumes of hydrogen. In three quar- 
ters of an hour there was a diminution of 2.5, which indicates 
1.6 hydrogen. 
These experiments were made in a tube of 0.4 inch internal 
diameter, divided into deci-millilitres, with such accuracy, that 
I could measure to within one quarter of a deci-millilitre, or the 
650th of a cubic inch In a tube of such small diameter, a 
much longer time is requisite for perfect action than in a more 
capacious vessel, since in ajar of 1.3 inch diameter, the effect 
is quite complete in five minutes. In all such experiments as 
the preceding, where great nicety of observation is necessary, 
the thermometer was always observed, and due correction made 
for the least difference. The duration of the experiments was 
not considerable enough to render barometrical observations 
requisite, more particularly as I drew no inference from single 
experiments. I think it then fair to conclude, that hydrogen 
may be detected in atmospheric air by platinum, when it does 
not exceed T t<jth of the whole volume; it follows too, if my 
experiments are not in fault, and I took all possible care to avoid 
error, that even the quantity of hydrogen under such circum- 
stances is exactly indicated. 
A mixture of 6 volumes of oxygen to 1 hydrogen was fired 
by electricity, and a platinum ball was brought in contact with 
the residue, but occasioned no diminution. 
A mixture of 8 volumes of oxygen to 1 hydrogen was fired 
by electricity. The residue was not at all diminished by pla- 
tinum. 
A mixture of 9 volumes of oxygen to 1 of hydrogen was fired 
by electricity. The diminution was quite to the sufficient ex- 
tent, nor had platinum any effect upon the residue. 
In a mixture of 11 parts of oxygen with 1 of hydrogen, elec- 
tricity occasioned only a feeble detonation, attended with par- 
tial decrease of volume, but a platinum ball caused formation of 
water in the residue. 
