decompounding fixed Air. 303 
volatile alkali, as might be expected, I could not decompose 
it, although I transmitted boiling hot phosphorus through a 
very long tube, containing mild volatile alkali. 
Experiments with Phosphorus applied to Quick-lime, and 
caustic fixed Alkalies. 
I need not explain that these experiments must confirm or 
invalidate the conclusion above drawn, that carbonic acid was 
decomposed by phosphorus applied to mild alkalies, and earths 
which contain this elastic fluid. 
As the quick-lime which can be procured in London must 
contain both water and carbonic acid, I exposed a quantity of 
this earth 48 hours to the fire of a reverberatory furnace, by 
which it was contracted to half its former bulk, and was di- 
minished in its weight ; it was, however, still soluble in acids, 
and afforded no carbonic acid. In the manner above described, 
I exposed 240 grains of it, with 60 grains of phosphorus, to 
heat in a coated glass tube. On breaking the tube, when cold, 
I found at the bottom about 30 grains of blackish and white 
powder ; and above that, to the extent of four or five inches, 
was a rose-coloured powder, which by its contact with air 
soon became of a reddish brown colour ; above this was the 
quick-lime, scarcely altered in its colour, but it had, like the 
rest of the powder in the tube, an alliaceous smell. On tast- 
ing a little of this reddish powder, I was surprised by its ex- 
ploding upon my tongue. I threw a few grains of it into se- 
veral ounces of cold water, it did not seemingly dissolve, or 
turn black, but in a few minutes emitted air-bubbles, which 
rose to the surface of the water, and then burst and exploded, 
R r 2 
