Abstract

A review of the first hundred years of Chemical Abstracts Service (CAS) reviews its significance and role as: (i) a witness to the changes in international scientific leadership; (ii) a classical example of scientific documentation; (iii) a general catalogue of chemical molecules in our natural and artificial world; (iv) a close ally of chemical and pharmacological industries; and (v) a paradoxically unsettled agent at a crossroads of the digital world. The uncertain future of CAS also symbolizes the uncertainty that reigns in scientific communication nowadays.