One of the British Museum Laboratory's long term projects is an investigation into the reliability of bone and antler as source materials for dating. A number of measurements on such materials are reported here. In all cases, only the organic fraction of the sample was used as a source of carbon, and the procedure adopted was as follows: Sample was broken into small pieces, either by course grinding or pounding in a mortar, and was treated with cold dilute hydrochloric acid in order to remove carbonates and to decalcify the material. Resulting granular gel was washed thoroughly by repeated soaking with cold water and was finally dried, prior to combustion.