Laboratory Methods of Organic Chemistry - Sciencemadness Dot Org

420 LITBKATUKB OF ORGANIC CHEMISTKY
statement of melting or boiling point, also the place in Beilstein
where more detailed information is available. Since Kichter's work
covers more ground than that of Beilstein, of which the third edition
with supplementary volumes only includes the literature up to
July 1, 1899, Richter gives references to the original literature for
the material which was lacking in Beilstein.
The five-volume work of Stelzner forms the continuation of
Richter's formula lexicon. It covers the literature up to the year
1921 and is arranged on the same plan as Richter's, but gives in
addition a brief description of the individual substances, their
constants and reactions, after the fashion of Beilstein.
The indexing of organic compounds described since 1922 has been
taken over by the Chemisches Zentralblatt, which follows the system
hitherto discussed. The collective indexes of this journal for 1922 to
1924,1925 to 1929, and 1930 to 1934 continue the classifying work of
M. M. Richter. In these indexes the references are to the Zentralblatt
itself. Bach year of the Zentralblatt, from 1925 onwards, contains
a formula index covering the annual increment of literature abstracted
in this comprehensively planned journal. These formula
indexes are amalgamated every few years into a collective index and
individually they constitute the reference works for the period which
has elapsed since the appearance of the last collective index. Consequently,
when it is desired to have complete information from the
whole literature about an organic substance, the following works
must be consulted at the present day :
1. Richter's Lexikon.
2. Stelzner, 1911-1921.
3. Collective Indexes of the Chemisches Zentralblatt, volumes vi.,
1922-1924, vii., 1925-1929, and viii., 1930-1934.
4. Formula indexes to the Zentralblatt for the years 1935, etc.
Conscientious study of the literature is indispensable to the
organic chemist. After a little practice the trouble of looking up
references becomes inconsiderable, and a thorough knowledge of the
literature on any particular point is of quite extraordinary value.
It may spare the worker the irritation of trying unsuitable preparative
methods which he may be tempted to apply because he has
neglected to look up a good one hidden in the literature. Likewise,
the danger of rediscovering already known compounds can only be