“…6. There are, of course, times where first and zero order cannot be distinguished in (a) Anhydi-ate formation at 40' ( 8 ) (27)] to be first order and amenable to Arrhenius plotting. The approach to equilibrium reported by Takahashi and Yamamoto (52) in the case of isomerization of vitamin DO to isocalciferol and isotachysterol is the consequence of the chemistry of reaction, as is the high temperature equilibrium approached by fumagillin reported by Garrett (49).…”