Several accounts from the 1500s describe smallpox inoculation as practiced in China and India (one is referred to in volume 6 of Joseph Needham's Science and Civilisation in China). Glynn and Glynn, in The Life and Death of Smallpox, note that in the late 1600s Emperor K'ang Hsi, who had survived smallpox as a child, had his children inoculated. That method involved grinding up smallpox scabs and blowing the matter into nostril. Inoculation may also have been practiced by scratching matter from a smallpox sore into the skin. It is difficult to pinpoint when the practice began, as some sources claim dates as early as 200 BCE.