The flows driven by buoyancy due primarily toconcentration gradients, INI >> 1, can be sorted out inan identical way. In the interest of brevity, however, wereport only the main conclusions of this second half ofthe scale analysis by drawing attention to the symmetryproperties of the governing equations (4)-(7). Theseproperties indicate that the scales of class 2 flows can beobtained from the scales of class 1 flows through thesimple transformation