Chemical Abstracts (Printed)
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The Chemistry Library has a complete run of printed Chemical Abstracts (CA) from 1907 through 2001. We now rely on the electronic version available via SciFinder Scholar. Chemical Abstracts is shelved in the center of the library, in reference ranges R1-R5. The Collective Indexes are shelved in ranges R1-R3. |
Parts of Print CA
Abstracts
CA is published weekly, and there are 26 weekly issues per "volume". Each Abstract issue is divided into
80 Subject Sections. Each abstract appears in just one section, based on the novelty of the process or substance being reported in the literature. Each weekly issue contains indexes by author, subject keyword (not official headings), and patent number. Individual issue indexes are superseded first by a volume index published every six months, and then by the Collective Index (see below). The Chemistry Library no longer subscribes to the print weekly issues.
Collective Indexes
Every five years CAS publishes a Collective Index (CI), which supersedes the semi-annual indexes for the previous 5-year CI period. The 14th CI was published in 2002 and covers the years 1997-2001. The library has all Collective Indexes up to this point. They are divided into:
- Author Index, 1907-
- Subject Index 1907-71 (included chemical substance names through 1971)
- Chemical Substance Index, 1972- (includes all CA Index Names used during the specific index period)
- General Subject Index, 1972- (includes all subject and compound-class terms that are not systematic CA Index Names)
- Formula Index, 1920-
- Patent Index, 1907-
Index Guides
The Index Guide for each Collective Index period provides cross-references from commonly used chemical names to official CA Index Names (with registry numbers) used in the corresponding Chemical Substance Index. It also serves as a thesaurus of all controlled-vocabulary subject headings used in the General Subject Index. The Index Guide should always be consulted before looking up a chemical name or subject term in the Collective Indexes.
Ring Systems Handbook
The RSH leads you from a ring or cage structure to the CA Index Name and Registry Number of a ring parent compound, for searching in the Chemical Substance Index. Entries are in ring analysis order and are indexed by molecular formula and Index Name.
Registry Handbook
The Registry Handbook - Number Section is a cumulative numerical listing of all registry numbers assigned to chemical substances from 1965 forward. If you have only a registry number and need the CA Index Name for that compound, look it up here first and then use the name to consult the Chemical Substance Indexes. A corresponding Names Section (available on microfiche) provided registry numbers for several hundred thousand of the most-indexed common names.
CASSI
CASSI (Chemical Abstracts Service Source Index) is the comprehensive and retrospective list of sources that have been indexed by Chemical Abstracts since it began in 1907. It includes journals, books, conferences, and other series, arranged by CA abbreviation. This is the source you use to translate journal title abbreviations into full titles for searching in the library catalog and other finding aids. CASSI is published every five years and is located at the Circulation Desk.
Using CA
- Select an appropriate Index volume based on the type of search you want to do (author, substance, or subject) and the time period desired.
- Author: Entries are arranged by last name, then by first and second initials (not by first name). Qualifying text is the title of the document. Coauthors are cross-referenced to first author.
- Formula: Entries contain only abstract numbers unless there is a large number of them, and no qualifying text. It's best to use the Formula Index to get the corresponding CA Index Name, then look up that name in the corresponding Chemical Substance or Subject (1907-71) index, where the entries are more detailed. Formulas are listed in Hill order.
- Chemical Substance name: Start with the Index Guide to see if there's an entry for the name you have. If not, use the Formula Index or Ring Systems Handbook to get the name. In the CSI you must use only the specific CA Index Name for that CI period. There are no cross references to earlier or generic names. Names are arranged by "parent" (the structural skeleton) followed by substituents and modifications. Qualifying text in each entry indicates what the document is primarily about, followed by an abstract number. About 600 of the most frequently indexed compounds are called "Qualified Substances." Their document entries are grouped into seven categories: Analysis, Biological studies, Occurrence, Preparation, Properties, Reactions, Uses and miscellaneous.
- Subject term: Always check the Index Guide first to find an appropriate term to look up in the Subject Index (1907-71) or General Subject Index (1972- ). Classes of compounds (e.g. Carcinogens), undefined compounds and mixtures (e.g. Gasoline), processes, plant/animal species, and other general topical terms are found in this index, along with cross references and scope notes.
- Patent number: Arranged by issuing country/organization, then by patent number. CA abstracts only the first member of a patent family, and links later equivalent patents to this parent patent. Equivalents are cross-referenced to the parent. Prior to 1981 the equivalents were listed in the Patent Concordance.
- Note Abstract Numbers from the entries of interest. Abstract numbers prior to 1967 are in the format V:Cp where V is the CA volume number, C is the sequential column number, and p is the position in that column where the abstract begins. Abstract numbers after 1967 have the format V:Nc, where V is the CA volume number, N is the sequential abstract entry number, and c is a control character you can ignore. Abstract numbers prefixed "R" indicate a review; "P" indicates a patent.
- Go to the corresponding Abstracts volume and look up the abstract by its number.
- Repeat this process for earlier or later index periods. Remember that Index Names and subject headings changed over time, so consult the Index Guide for each CI period.
Is there still a reason to use print CA?
In most cases, no. CA's size and complexity can confuse even the experienced searcher. It's much faster and more convenient to use a database version, such as SciFinder Scholar. There are however some occasions when print CA is still useful:
- When you need to look up a pre-1967 CA abstract number (e.g. CA 53:2185a), you must use the print version; these numbers are not searchable or displayed in SciFinder. See the SciFinder FAQ for more information.
- Chemical structure graphics that appeared within the printed abstracts are not duplicated in SciFinder.
- The highly structured organization of the Chemical Substance Indexes is easier to browse than trying a hit-or-miss chemical structure, name or formula search in SciFinder, especially when searching for salts, esters, and other derivatives of parent compounds, as well as multicomponent substances such as copolymers, alloys, tabular inorganics, and mixtures. In these cases, be sure to start with the Index Guide and/or Ring Systems Handbook to find the proper name entry in the CSI.
- Pre-1967 print CA is easier to navigate than the post-1967 volumes, mainly due to its smaller size.
Help Using CA
See the
CA Tips page. A booklet called
"How To Search Printed CA" is available in the library with the CA indexes.