In an article in this Journal' Smith rightly bemoaned the absences in chemistry texts of demonstrations of entropy Maxima at equilibrium. In the United Kingdom, the introduction of a new chemistry course for 16-18-year-old students has provided the opportunity to rectify this omission. The ~revised Nuffield chemistry course2 us& a simple statistical approach to entropy as a unifying idea in its treatment of thermodynamics.-Entropy changes are used to explain the direction of chemical reactions and why they "stop" before completion.