his
demonstrations, and disgusted with the series of observations and
experiments which were brought forward one month to be overturned the
next. In November there was a Zingeberic acid, which in January was
shown to have no existence; one year there was a vegetable acid, which
the next was shown to be the same as an acid known thirty years ago; to-
day a man was celebrated for having discovered a new metal or a new
alkali, and they flourished like the scenes in a new pantomime only to
disappear. Then, the great object of the hundred triflers in the science
appeared to be to destroy the reputation of the three or four great men
whose labours were really useful, and had in them something of dignity.
And, there not being enough of trifling results or false experiments to
fill up the pages of the monthly journals, the deficiency was supplied by
some crude theories or speculations of unknown persons, or by some ill-
judged censure or partial praise of the editor.

_The Unknown_.--I deny _in toto_ the accuracy of what you are advancing.
I have already shown that real philosophers, not labouring for profit,
have done much by their own inventions for the useful arts; and, amongst
the new substances discovered, many have had immediate and very important
applications. The chlorine, or oxymuriatic gas of Scheele, was scarcely
known before it was applied by Berthollet to bleaching; scarcely was
muriatic acid gas discovered by Priestley, when Guyton de Morveau used it
for destroying contagion. Consider the varied and diversified
applications of platinum, which has owed its existence as a useful metal
entirely to the labours of an illustrious chemical philosopher; look at
the beautiful yellow afforded by one of the new metals, chrome; consider
the medical effects of iodine in some of the most painful and disgusting
maladies belonging to human nature, and remember how short a time
investigations have been made for applying the new substances. Besides,
the mechanical or chemical manufacturer has rarely discovered anything;
he has merely applied what the philosopher has made known, he has merely
worked upon the materials furnished to him. We have no history of the
manner in which iron was rendered malleable; but we know that platinum
could only have been worked by a person of the most refined chemical
resources, who made multiplied experiments upon it after the most
ingenious and profound views. But, waiving all common utility,