Abstract
Dr. R.H. Brown noted reports by AMS (accelerator [or atomic] mass spectrometry) laboratories of measurable ¹⁴C activity in samples such as anthracite coal. His statement that such results were "unexpected" suggests that he perhaps does not fully understand the history and nature of low-level ¹⁴C counting technology and therefore may have misunderstood the major point of these reports. In an earlier draft of this response, I had provided a brief explanation of the basic principles of ¹⁴C counting instrumentation and how the development of AMS technology relates to conventional approaches. However, the editor has requested a much-shortened comment. For those interested in a more complete explanation, there is a large literature, a small portion of which has been listed in the bibliography of a recent volume on radiocarbon dating (1) which was reviewed by Dr. Brown in a previous issue of ORIGINS.