37 1 
with a large voltaic battery. 
carbonate, caustic lime, and obtained also what he considered 
to be cast steel; whence he concluded that the carbon neces- 
sary to convert the iron into steel had not been furnished, 
as Clouet supposed, by decomposition of the carbonic acid, 
but that it had found its way from the ignited gas of the 
furnace to the iron. This result occasioned suspicions of the 
accuracy of the deductions from the experiment with the dia- 
mond ; and Mr. Mushet accordingly, at the suggestion of 
the editor of the Philosophical Magazine, repeated the ex- 
periment made at the Polytechnic School, only keeping out the 
diamond. The results (for he made several experiments) 
uniformly gave him good cast steel, whence he concludes 
that we are still without any satisfactory or conclusive proof 
of the steelification of iron solely by means of the diamond ; 
and adds that he doubts whether the diamond afforded even one 
particle of carbon to the iron. The details of both Clouet’s and 
Mushet’s experiments, may be found in the fifth volume of the 
Philosophical Magazine. Sir George M‘Kenzie repeated both 
Clouet’s experiments and those of Mr. Mushet, and obtained 
results confirming the conclusions of the French chemist. 
The labours of this gentleman indeed seem sufficiently con- 
clusive; but, if a doubt should remain, it occurred to Mr. 
Pepys, that the battery would afford an experimentum crucis 
on the subject; and his ingenuity readily suggested a mode 
of making it, every way unobjectionable. He bent a wire of 
pure soft iron, so as to form an angle in the middle, in which 
part he divided it longitudinally, by a fine saw. In the open- 
ing so formed, he placed diamond powder, securing it in its 
situation by two finer wires, laid above and below it, and 
kept from shifting, by another small wire, bound firmly and 
3 B 2 
