[frodsham]

Originally posted by ewmayer
I know this doesn't alter the argument, but, just for the record, it's really the Loschmidt constant, as Avogadro never made any estimate of the number itself.

Not really, because if you read

Originally posted by Reboot It
See for example the National Physical Laboratory website's useful PDF reference guide to fundamental physical constants and conversion factors.

you'll find

Loschmidt constant (Na/Vm) ~= 2.686 7775 x 10^25 m^-3

The "mistake" was to call it Avogadro's constant rather than [the] Avogadro constant.

Mathematical pedantry can be such fun.