is
introduced artificially into aerated waters. It is formed by the
combination of carbon with one of the elements of the air (oxygen), and
is called by chemists carbonic acid. This substance is produced
whenever carbon, or substances which contain carbon, are burned in
contact with the air; and not the slightest trace of it is ever found,
if the substance burned does not contain carbon.
After
this grand fact had been established, it was very easy to find out if
the diamond contained carbon, and also whether this was its sole
constituent. To settle the first question, the celebrated Lavoisier had
recourse to the experiment represented by
Fig. 31
A
bell-glass filled with oxygen was reversed in a basin containing
mercury. A cupel placed at the extremity of a little column received
the diamond, upon which the sun's rays were concentrated by means of a
burning-glass.
The
diamond disappeared; and it was proved that the glass, which at the
commencement of the experiment had contained no trace of carbonic acid,
contained a great quantity after the disappearance of the diamond. The
diamond then contained carbon as one of its elements. Davy did not
remain satisfied with this.
By analogous experiments he showed that the combustion of the diamond in oxygen produced
