physicists.... Volta, in that Italy which had been the cradle of the
new knowledge, discovered the principle of its true theory in a fact
which reduces the explanation of all the phenomena in question to the
simple contact of two substances of different nature. This fact became
in his hands the germ of the admirable apparatus to which its manner
of being and its fecundity assign one of the chief places among those
with which the genius of mankind has enriched physics."

Shortly afterwards, our amateur would learn that Carlisle and
Nicholson had decomposed water by the aid of a battery; then, that
Davy, in 1803, had produced, by the help of the same battery, a quite
unexpected phenomenon, and had succeeded in preparing metals endowed
with marvellous properties, beginning with substances of an earthy
appearance which had been known for a long time, but whose real nature
had not been discovered.

In another order of ideas, surprises as prodigious would wait for our
amateur. Commencing with 1802, he might have read the admirable series
of memoirs which Young then published, and might thereby have learned
how the study of the phenomena of diffraction led to the belief that
the undulation theory, which, since the works of Newton seemed
irretrievably condemned, was, on the contrary, beginning quite a new
life. A little later--in 1808--he might have witnessed the discovery
made by Malus of polarization by reflexion, and would have been able
to note, no doubt with stupefaction, that under certain conditions a
ray of light loses the property of being reflected.

He might also have heard of one Rumford, who was then promulgating
very singular ideas on the nature of heat, who thought that the then
classical notions might be false, that caloric does not exist as a