Pierre Curie did an experiment and strapped a tube of radium to his arm for a long period of time. When lesions formed and it was discovered that radium could harm healthy tissue, they wondered if it might destroy diseased tissue. Radioactive sources were inserted into the body or strapped to the surface. This was named-

Radioactive therapy

Explanation:

Radioactive materials were believed to have medicinal properties like having antibacterial effect and ability to cure a wide range of ailment. Radioactive therapy was marketed with the idea that humans had a high tolerance level for the radioactivity. It was not until research showed that the tolerance level was very much lower than thought, and the lethal side effects of radioactivity understood, that radioactivity was seen as highly dangerous, and handled with extreme caution and precautions.

this is poiselle's equation from fluid mechanic in physics. mech eng