  The cumulants of thermal variables are of general interest in physics due to
their extensivity and their correspondence with susceptibilities. They become
especially significant near critical points of phase transitions where they
diverge along with the correlation length. Cumulant measurements have been used
extensively within the field of heavy-ion physics, principally as tools in the
search for a hypothetical QCD critical point along the transition between
hadronic matter and QGP. The volume of individual heavy-ion collisions can be
only partially constrained and, as a result, cumulant measurements are
significantly biased by the limited volume resolution. We propose a class of
moments called strongly intensive cumulants which can be accurately measured in
the presence of unconstrained volume fluctuations. Additionally, they share the
same direct relationship with susceptibilities as cumulants in many cases.
