A review is presented of work carried out in the author's laboratory c
oncerning the thermodynamic and electrical transport phenomena in magn
etite. The need for careful compositional control of single crystal gr
owth is emphasized. With increasing deviations from the ideal Fe3O4 co
mposition the Verwey transition suddenly shifts from the first order t
o a higher order regime. This hitherto unrecognized feature is documen
ted by a variety of experimental techniques and is rationalized in ter
ms of a single formalism based on a mean field theoretic approach. The
agreement between theory and experiment is very good. Various aspects
of the theoretical analysis are discussed in detail; the formalism is
of much more general appreciability than the Limited use to which it
was put in the resolution of the Verwey problem.