lost in 14 days.

+9. Second Experiment.+--(_a._) I repeated the preceding experiment with
the same quantity of liver of sulphur, but with this difference that I
only allowed the bottle to stand a week, tightly closed. I then found
that of 20 parts of air only 4 had been lost. (_b._) On another occasion
I allowed the very same bottle to stand 4 months; the solution still
possessed a somewhat dark yellow colour. But no more air had been lost
than in the first experiment, that is to say 6 parts.

+10. Third Experiment.+--I mixed 2 ounces of caustic ley, which was
prepared from alkali of tartar and unslaked lime and did not precipitate
lime water, with half an ounce of the preceding solution of sulphur
which likewise did not precipitate lime water. This mixture had a yellow
colour. I poured it into the same bottle, and after this had stood 14
days, well closed, I found the mixture entirely without colour and also
without precipitate. I was enabled to conclude that the air in this
bottle had likewise diminished, from the fact that air rushed into the
bottle with a hissing sound after I had made a small hole in the cork.

+11. Fourth Experiment.+--(_a._) I took 4 ounces of a solution of
sulphur in lime water; I poured this solution into a bottle and closed
it tightly. After 14 days the yellow colour had disappeared, and of 20
parts of air 4 parts had been lost. The solution contained no sulphur,
but had allowed a precipitate to fall which was chiefly gypsum. (_b._)
Volatile liver of sulphur likewise diminishes the bulk of air. (_c._)
Sulphur, however, and volatile spirit of sulphur, undergo no alteration
in it.

+12. Fifth Experiment.+--I hung up over burning sulphur, linen rags
which were dipped in a solution of alkali of tartar. After the alkali
was saturated with the volatile acid, I placed the rags in a flask, and
closed the mouth most carefully with a wet bladder. After 3 weeks had
elapsed I found the bladder strongly pressed down; I inverted the flask,
held its mouth in water, and made a hole in the bladder; thereupon water
rose with violence into the flask and filled the fourth part.

+13. Sixth Experiment.+--I collected in a bladder the nitrous air which
arises on the dissolution of the metals in nitrous acid, and after I had
tied the bladder tightly I laid it in a flask and secured the mouth very
carefully with a wet bladder. The nitrous air gradually lost its
elasticity, the bladder collapsed, and bec