You must be ready to give up even the most attractive ideas when experiment shows them to be wrong.

I continue coupling a plate of silver with one of zinc, and always in the same order... and place between each of these couples a moistened disk. I continue to form a column. If the column contains about twenty of these couples of metal, it will be capable of giving to the fingers several small shocks.

What is it possible to do well, in physics particularly, if things are not reduced to degrees and measures?

Each metal has a certain power, which is different from metal to metal, of setting the electric fluid in motion.