*6 Mr. Davy's Experiments on 
case, except when the sodium was covered by a film of 
naphtha. I burnt two grains of sodium in 8 cubical inches of 
oxygene : nearly two cubical inches of oxygene were absorbed, 
and soda in a state of extreme dryness, so that it could not 
be liquified by a heat below redness, formed. This soda did 
not give out an atom of carbonic acid, during its solution in 
muriatic acid. Three grains of sodium were made to act 
upon water ; they decomposed it with the phasnomena which 
I have described in the Bakerian lecture for 1807. Nearly 6 
cubical inches of hydrogene were produced. No charcoal 
separated ; no carbonic acid was evolved, or found dissolved 
in the water. Whether the metals of potash or soda were 
formed by electricity, or by the action of ignited iron on the 
alkalies, the results were the same. When charcoal is used 
in experiments on potassium or sodium, they usually contain 
a portion of it in combination, and it appears from M. Curau- 
dau's method of decomposing the alkalies, that his metals 
must have been carburets not of potash and soda, but of po- 
tassium and sodium. 
M. Ritter's argument in favour of potassium and sodium, 
being compounds of hydrogene, is their extreme lightness. 
This argument I had in some measure anticipated, in my 
paper on the decomposition of the earths ; no one is more 
easily answered. Sodium absorbs much more oxygene than 
potassium, and on the hypothesis of hydrogenation, must con- 
tain much more hydrogene ; yet though soda is said to be 
lighter than potash, in the proportion of 13 to 17 nearly,* yet 
sodium is heavier than potassium in the proportion of 9 to 7 at 
least. 
* Hassenfratz, Anna!, de Chezn. Tom. XXVIII. page u.. 
