PITY poor Johann Loschmidt, an Austrian scientist who calculated in 1865 that the number of molecules in a mole of gas is 6 × 1023. This figure will be familiar to anyone interested in chemistry as Avogadro’s number.
And yet the Italian chemist Amedeo Avogadro never calculated it. His name became attached to the number some years after Loschmidt’s death, when a few chemists campaigned to name it in Avogadro’s honour. The history of science is littered with such injustices over the credit taken for discoveries, so much so that historians of science have taken to categorising the slights.…
