  Within the Tsallis thermodynamics' framework, and using scaling properties of
the entropy, we derive a generalization of the Gibbs-Duhem equation. The
analysis suggests a transformation of variables that allows standard
thermodynamics to be recovered. Moreover, we also generalize Einstein's formula
for the probability of a fluctuation to occur by means of the maximum
statistical entropy method. The use of the proposed transformation of variables
also shows that fluctuations within Tsallis statistics can be mapped to those
of standard statistical mechanics.
