 His most influential work, "Osteologia nova, or some new Observations of the Bones", was the first report of the microscopic structure of bone.This work was greatly praised by the Italian scientist, Giorgio Baglivi, and was published in several editions in Frankfurt and Amsterdam.In February 1700, Havers reported to the Royal Society on a Chinese practice of smallpox inoculation, which involved inhaling dried matter from a smallpox pustule.