nt
heat. Furthermore, Watt merely suggested the possible composition
without proving it, although his idea was practically correct, if we can
rightly interpret the vagaries of the nomenclature then in use. But
had Watt taken the steps to demonstrate his theory, the great "Water
Controversy" would have been avoided. Cavendish's report of his
discovery to the Royal Society covers something like forty pages of
printed matter. In this he shows how, by passing an electric spark
through a closed jar containing a mixture of hydrogen gas and oxygen,
water is invariably formed, apparently by the union of the two gases.
The experiment was first tried with hydrogen and common air, the oxygen
of the air uniting with the hydrogen to form water, leaving the nitrogen
of the air still to be accounted for. With pure oxygen and hydrogen,
however, Cavendish found that pure water was formed, leaving slight
traces of any other, substance which might not be interpreted as being
Chemical impurities. There was only one possible explanation of this
phenomenon--that hydrogen and oxygen, when combined, form water.

"By experiments with the globe it appeared," wrote Cavendish, "that when
inflammable and common air are exploded in a proper proportion, almost
all the inflammable air, and near one-fifth the common air, lose their
elasticity and are condensed into dew. And by this experiment it appears
that this dew is plain water, and consequently that almost all the
inflammable air is turned into pure water.

"In order to examine the nature of the matter condensed on firing a
mixture of dephlogisticated and inflammable air, I took a glass
globe, holding 8800 grain measures, furnished with a brass cock and an
apparatus for firing by electricity. This globe was well exhausted by
an air-pump, and then filled with a mixture of inflammable and
dephlogisticated air by shutting the cock, fastening the bent glass tube
into its mouth, and letting up the end of it into a glass jar inverted
into water and containing a mixture of 19,500 grain measures of
dephlogisticated air, and 37,000 of inflammable air; so that, upon
opening the cock, some of this mixed air rushed through the bent tube
and filled the globe. The cock was then shut and the included air fired
by electricity, by means of which almost all of it lost its elasticity
(was condensed into water vapors). The cock was then again opened so as
to let in more of the same air to supply the place of that de