Wikimedia
Wikipedia: Henry Cavendish
Wikipedia offers biographical information on the British scientist Henry Cavendish (1731-1810), credited with having discovered hydrogen, which he described as "inflammable air."
WebMD
Web Md: Autism Spectrum Disorders Health Center
The term "pervasive developmental disorders," also called PDDs, refers to a group of conditions that involve delays in the development of many basic skills. Most notable among them are the ability to socialize with others, to...