chalk only especially fine material is used after it's been additionally cleaned what remains as the museum informs visitors are mainly residues a planktonic form enough era these single celled animals had skeletons made of small calcite platelets when the organisms died they sank to the seabed and formed the chalk sediment. physiotherapist york snyder from sausan its has been using hogans medicinal chalk since the early one nine hundred ninety s. this natural product dissolved in water is said to stimulate the heart and circulation and have an anti inflammatory effect. on very few you know if it's used as a poultice on the back or joints warm or cold or if you're experiencing a rheumatic episode for instance it's applied cold or market for chronic conditions