CHEMISTRY

• Beilstein. Frankfurt: Beilstein Information, 1997–. A database of references to publications about organic compounds, based on Beilstein's Handbook for Organic Chemistry. The work covers organic chemistry research back to the eighteenth century, updated with the contents of current journals. Electronic versions are called variously CrossFire, MDL Commander, and Beilstein Online; one is also available through ChemWeb, below. Inorganic compounds are covered in Gmelin's Handbuch der Anorganischen Chemie, which is also available online as Gmelin Database.
• Chemical Abstracts. Columbus: American Chemical Society, 1907–. A comprehensive index to chemistry publications. Searches can be conducted by author, subject, chemical structure, formula, and more. Online access is provided through the services STN and SciFinder Scholar.

• ChemFinderhttp://chemfinder.cambridgesoft.com Databases for common types of chemicals, including physical property data and two-dimensional chemical structures. Though chemical structures, manufacturer's information, and organic syntheses published in a respected annual series can be searched at no cost, some of the databases at this site are available only by subscription.
• ChemWebhttp://www.chemweb.com Offers a wide variety of information, including breaking news and a preprint archive. Registration is required. Most of the material is free, but some journals and databases are available only by subscription.
• Molecule of the Monthhttp://www.chm.bris.ac.uk/motm/motm.htm Provides detailed graphic and textual information on molecules, from mustard gas to aspirin. Pages are contributed by chemists in universities and research labs around the world. Emphasis is on molecules of popular interest. The site is maintained by Paul May at the School of Chemistry, University of Bristol.
• NIST Chemistry WebBookhttp://webbook.nist.gov/chemistry Provides chemical structure and thermochemical data for over 6,500 organic and small inorganic compounds and over 9,800 reactions as well as a variety of spectra data. A service of the National Institute of Standards and Technology, the site is searchable by physical property, name, formula, and more.
• WebElements Periodic Tablehttp://www.webelements.com Offers information about elements based on the periodic table. The "professional edition" portion of the site provides data about physical, electronic, and nuclear properties as well as information about abundance, use, and more. The "scholar edition" presents similar information in a more accessible style. The site is maintained by Mark Winter at the University of Sheffield.

• Encyclopedia of Reagents for Organic Synthesis. Ed. Leo A. Paquette. 8 vols. Chichester: Wiley, 1995. Comprehensively covers over 3,000 reagents in alphabetical order. The work is indexed by formula, reagent structural class, and reagent function. Each article includes ring diagrams and a bibliography of research sources. The online version is called e-EROS.
• Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. 25 vols. New York: Wiley, 1991–. Provides in-depth articles on chemical properties, manufacturing, and technology. A fifth edition began publication in 2004. A single-volume concise edition is also available.
• Macmillan Encyclopedia of Chemistry. Ed. Joseph J. Lagowski. 4 vols. New York: Macmillan Library Reference, 1997. A wide range of brief, accessible articles on research and practical concepts in chemistry, including key ideas in the field, individual chemists and their contributions, and common chemical substances.
• Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals. Ed. Maryadele J. O'Neil. 13th ed. Whitehouse Station: Merck, 2001. Contains about 10,000 entries on chemicals, including many pharmaceuticals, as well as chemical formulas, properties, uses, and references to literature.
• World of Chemistry. Ed. Robin V. Young. Detroit: Gale Group, 2000. A collection of articles on theories, discoveries, concepts, and key scientists in chemistry.