In Canada, most works pass into the public domain after fifty years following the end of the calendar year in which the author died. However, while a work may be in the public domain, a specific edition or image of the work may be under copyright. This is important to remember.
Canadian Copyrights Database. To find out if books are in the public domain, you can search the Canadian Copyrights Database.
CDC Public Health Image Library. This image collection contains photographs, illustrations, and multimedia files. There is both a general and an advanced search feature.
National Cancer Institute: NCI Visuals Online. The National Cancer Institute provides an extensive image collection. You can browse, search, and temporarily save images. It includes many anatomical images not related specifically to cancer.
The Cancer Imaging Archive. A large archive of medical images of cancer accessible for public download from The Frederic National Laboratory for Cancer Research (FNLCR). Registering is free. All images are stored in DICOM file format. The images are organized as "Collections", typically patients related by a common disease (e.g. lung cancer), image modality (MRI, CT, etc) or research focus. Some collections in this archive have use restrictions. More information is available on their data usage policies and restrictions page.
National Eye Institute: NEI Photos and Images. The search feature for this collection allows you to select from eye conditions, anatomy, or diagnostic/treatments. It also links out to NEI YouTube videos and other image resources.
Digital Media Database: National Human Genome Research Institute. This large database contains downloadable high-resolution photographs, graphics and video files related to the field of genomic research and the activities of the National Human Genome Research Institute. Images are sorted into the following categories: people, events, lab/technology, plants, animals, microorganisms, graphics, and videos.
National Institute of Dental and Craniofacial Research (NIDCR) Image Gallery. The NIDCR image gallery consists of images in three categories: Science, Oral Health, and NICDR Staff. It contains both photographs and illustrations.
National Institute of General Medical Sciences (NIGMS) Image and Video Gallery. A collection of photographs, illustrations and videos. Images are downloadable in small, medium or large format.
NIH Images from the History of Medicine. This database provides access to over 70,000 images in the collections of the History of Medicine Division (HMD) of the U.S National Library of Medicine (NLM). The collection includes portraits, photographs, caricatures, genre scenes, posters, and graphic art illustrating the social and historical aspects of medicine dated from the 15th to 21st century. Some materials may be protected by United States or foreign copyright laws.
National Science Foundation (NSF) Multimedia Gallery. This image collection contains over 3,000 images, videos, audio files, and links to additional audio slideshows, interactive features, screensavers and other content that doesn't neatly fit into the categories of images, video and audio.
Library of Congress: Government Resources for Science Images and Videos. This website links to many government image collections. Topics include agriculture, astronomy and aeronautics, biology, conservation, earth sciences and geology, energy, engineering, health science and medicine, and the Library's own prints and photographs collection.
U.S. Government Flickr Photostream. This website is comprised of official U.S. federal, state, and local government photostreams on Flickr.