Here are some sites that provide access to digitized primary resources:
Gynaecology in Traditional Chinese Medicine: Selected Texts From McGill, A full-text searchable database that provides access to rare books and manuscripts written in classical (literary) Chinese dealing with gynaecology.
China : Trade, Politics & Culture 1793-1980 Contains unique manuscript material relating to the activities and observations of British and American diplomats, missionaries, business people and tourists in China from 1793 to 1980.
Western Medicine in China, 1800-1950 An open access resource hosted by Indiana University, connects to digital collections of Chinese hospital reports, 19th-early 20th century books by medical missionaries, and other resources.
The Chinese Recorder and the Protestant Missionary Community in China, 1867-1941 Includes a complete run of the Chinese Recorder, an important missionary journal which was first published in Fuzhou in 1867 and then in Shanghai from 1874 till 1941.
Medicine and Childbirth A guide to reading original Chinese, including treaties, medical manuscripts, and even a lady's mirror. From the University of Michigan.
Medicine and Public Health, from Morning Sun: A Website about the Cultural Revolution Contains images, documents, and multimedia resources.
Chinese Pamphlets The Hunter Collection consists of mass education materials published in Hong Kong and in Mainland China, particularly Shanghai, in the years 1947-1954, including approximately 200 cartoon books, pamphlets, postcards, and magazines, heavily pictorial in content.
Classics of Traditional Chinese Medicine The digital version of an exhibition at the National Library of Medicine of 2,000 volumes of Chinese medical classics.
Medical Photographs from the Wellcome Institute One of the world's richest and most unique collections, with themes ranging from medical and social history to contemporary healthcare and biomedical science.