Ce livre pr sente les r sultats d'une tude sur la polarisation et la double r fraction des cristaux trois axes obliques, effectu e par A. J. Angstr m. Les recherches ont t publi es dans les Acta Reg Soc Upsal, une revue scientifique su doise. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States...