No. 27: May-Jun 1983
You may not feel any north-directed nasal twinges, but the thin hard bones lining the human sinuses contain deposits of magnetic ferric iron. This discovery adds man to a long list of organisms from bacteria to birds known to possess localized accumulations of magnetic material. Experiments with these animals, including humans, seem to indicate a widespread ability to detect ambient magnetic fields. Some animals appear to use this sense for navigation. Whether humans do or do not is still a moot question.
(Baker, Robin R., et al; "Magnetic Bones in Human Sinuses," Nature, 301: 78, 1983.)