A History of Science — Volume 4Williams, Henry Smith
History
A History of Science — Volume 4
Williams, Henry Smith
Science -- History
It appears that something like a year before Cavendish made known his
complete demonstration of the composition of water, Watt communicated
to the Royal Society a suggestion that water was composed of
"dephlogisticated air (oxygen) and phlogiston (hydrogen) deprived of
part of its latent heat." Cavendish knew of the suggestion, but in his
experiments refuted the idea that the hydrogen lost any of its latent
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.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account