iron sulfate /oss/taxonomy/term/6079/all en The Powder of Sympathy /oss/article/history/powder-sympathy <p>Four hundred years ago Belgian physician Johann Baptist Van Helmont was persecuted by the Roman Catholic Church for promoting the use of the “Powder of Sympathy” that was supposed to treat wounds by applying it to a dressing that had previously covered the wound. The exact nature of the substance varied, but iron or copper sulfate seem to have been common ingredients. This folly was first proposed by physician and scoundrel Sir Kenelm Digby, but Van Helmont bought into the idea. Somehow the effect of the powder on the bloody dressing was to be communicated to the blood still in the body.</p> Fri, 25 Feb 2022 18:33:41 +0000 Joe Schwarcz PhD 9037 at /oss