Prof. DcebereinePs recent Discovery , to Eudiomeiry. 109 
It appeared to me at a very early period of this investigation’, 
that spongy platinum might be expected to produce the com- 
position and decomposition of gases, whenever the electric spark 
succeeded in doing so. Professor Doebereiner had himself found, 
that mixtures of carburetted hydrogen and carbonic oxide with 
oxygen gas were made to combine by this agent. MM. Du- 
long et Thenard have observed, that, in a mixture of hydro- 
gen and nitrous gas, spongy platinum occasioned the decompo- 
sition of the latter, with formation of water and ammonia ; and 
that it acted likewise on a mixture of hydrogen and nitrous 
oxide. My friend Mr Blundell, a most intelligent and promis- 
ing student of this University, has likewise noticed some interest- 
ing facts of the same nature. He finds that platinum causes 
hydrogen to unite with chlorine, and with the elements of eu- 
chlorine gas ; and has likewise observed other facts of a similar 
nature. In a few observations, read some weeks ago before the 
Royal Medical Society, I suggested the probability that the 
same agent would make iodine and hydrogen combine ; and 
though I have not myself had leisure to examine this subject 
with care, yet Mr Blundell informs me he has succeeded in 
forming hydriodic acid in this way. 
Several of these experiments I have myself repeated, and 
found perfectly correct. My attention, however, was chiefly 
directed to the action of platinum on mixtures of oxygen with 
olefiant gas, with coal gas, and with carbonic oxide. Notwith- 
standing the ingenious researches of Dr Henry, a method of se- 
parating hydrogen, light carburetted hydrogen, and carbonic 
oxide, from one another, is still a great desideratum in analyti- 
cal chemistry ; and I entertained some hope that platinum might 
prove useful in this point of view. My attempts to apply it to 
the analysis of these gases have failed, but as I have examined 
this subject with considerable care, it may not be uninteresting 
to relate some of the experiments. 
A jet of coal-gas, procured from the city gas-pipes, was 
thrown upon freshly ignited spongy platinum. At the first 
moment a particle of the metal became luminous, but the light 
disappeared on the instant, nor have I been able, upon any sub- 
sequent occasion, to reproduce the same phenomenon, though 
platinum freshly reduced, and in a state of great activity, was 
