Why do priests use incense at Mass? — A reader in AlexandriaIncense is an aromatic substance which is the resin from certain trees. When burned over charcoal, the incense produces a sweet smelling aroma. To make the smoke thicker and to enhance the fragrance, sometimes other perfumes are blended with the incense.The use of incense in the ancient world was common, especially in religious rites where it was used to keep demons away. Herodotus, the Greek historian, recorded that it was popular among the Assyrians, Babylonians and Egyptians. In Judaism, incense was included in the thanksgiving offerings of oil, grain,...