ChemSpider is a free resource that links together compound information across the web, providing data such as structural and chemical formulas, properties of chemicals, and links to PubMed article citations, among other information.
The NCHS website is a rich source of data for researchers, teachers, and students who are interested in analysis of NCHS data as well as documentation and methodology of NCHS survey and data collection systems.
The site for the Kennedy Institute of Ethics at Georgetown University contains bibliographies, free citation databases (ETHXWeb, GenETHX, Syllabus Exchange), the International Bioethics Organizations database, and educational resources on biomedical and professional ethics.
PubChem is the world's largest collection of freely accessible chemical information. Search chemicals by name, molecular formula, structure, and other identifiers. Find chemical and physical properties, biological activities, safety and toxicity information, patents, literature citations and more.