Most of the 14C measurements reported here were made between October 74 and March 76. The usual procedures and methods of sample preparation are those described in R, 1964, v 6, p 194-196. The electronic apparatus was constructed by J Galliot from results of studies on background of proportional counters (Delibrias & Rapaire, 1967) and was described briefly in R, 1966, v 8, p 286-291.