This paper sheds, through the concepts of demography, a differnet light on the study of scientific journals. Without leaving aside the major role played by scientific journals, such an approach allows for the use of tools which are at the basis of information watch in research. Different key variables are used such as the date of its birth of a journal (resp. its date of death), the migration to other fields of knowledge or to other audiences... A certain number of indicators are exposed such as the rates (gross or net) of new publications or deaths. Some applications are proposed.