experiences lasting more than a few minutes. In
a note to the Academy of Sciences, I established
that constancy and duration could be achieved
when carbon surfaces were of sufficient size,
solutions were properly prepared, and zincs
Some of your batteries were open-topped and
others were in glass jars. How did they work?
My moist-cell battery worked in a glass vase with
two flat disks: one zinc and one copper. Between
these disks were blotting-paper washers. The
lower washers were impregnated with a saturated solution of copper sulfate, while the upper
washers contained a solution of zinc sulfate.
A copper rod insulated in ebonite plastic held
everything in place. Wetting the disks put the
element into action. Being very regular, this battery was especially advantageous for telegraphy
and medical instruments. As you can imagine,
constant and continuous current was critical
during surgery, and my batteries achieved that.
One of the most practical, simple, and well
known was the Trouvé-Callaud battery made of
copper, zinc, and a copper sulfate solution. It
was designed for medical uses. Constructed at
a more reasonable cost than other batteries and
generating about 1 volt, it also could be employed
in alarms, telegraphs, and telephones.
Arthroscopes, laparoscopes, and ultrasound
are today’s high-tech medical tools. Are such
devices really new?
Mais non! I invented polyscopes (illuminated
endoscopes) and photophores (medical
headlamps) beginning in 1869. Polyscopes let
physicians explore inaccessible parts of the
human body, and photophores illuminated and
reflected more easily accessible cavities. I was
the first to light the cavities of the human body
by means of platinum wire heated to an incandescent state by an electric current. This made
diagnosis more accurate.
Although I developed both petrol- and electric-powered devices, the electric ones came into
widespread use during surgery and in physiology
laboratories and dentists’ and gynecologists’
offices. Societies and exhibitions around the
world honored me with medals and diplomas.
I also created instruments for removing tumors
and extracting projectiles, as well as for cauterizing. I do not wish to describe too graphically
the instruments I customized to each organ. (For
those interested, I suggest my illustrated Manuel
For my batteries and medical instruments
I made cabinets, portable cases, and even
a tapestry cover that made a pedal-operated
electro-cautery device look like an ottoman.