The growing interdependence of the sciences was one of the outstanding characteristics of the first half of the twentieth century. "Inevitably," Dr. Leicester points out, "this expanded vision led to closer contacts among chemists of every speciality, and also with scientists in other fields. Physics and physical chemistry were applied to organic compounds, and new substances that could not have been foreseen by the older theories were prepared. Reaction mechanisms were generalized. New borderline sciences sprang up. Chemical physics and biochemistry became sciences in their own right....