Experiment Station Record, Volume 92, January-June, 1945 Page: 1

EXPERIMENT STATION RECORD
Vol. 92 JANUARY 1945 No. 1
RECENT WORK IN AGRICULTURAL SCIENCE1
AGRICULTURAL AND BIOLOGICAL CHEMISTRY
Hackh's chemical dictionary [American and British usage], revised and
edited by J. GRANT (Philadelphia: Blakiston Co., 1944, 3. ed., rev., pp. 925+, ills.
270).-This dictionary, containing more than 57,000 definitions, presents clear statements
of chemical theories, laws, and rules; accurately describes ,the elements,
compounds, minerals, drugs, vegetable and animal products; lists concisely the
important reactions, processes, and methods; mentions briefly chemical apparatus,
equipment, and instruments; and notes the names of investigators who have built up
the science. Also included is the collateral vocabulary of physics, astrophysics.
geology, mineralogy, botany, zoology, medicine, and pharmacy, and, also, the pertinent
jargon of industry, mining, and commerce. In the present edition the whole
dictionary has been completely revised and brought up to date, with especial care to
balance the treatment from the American and British point of view. There has been
no important departure from the treatment in earlier editions except for the omission
of pronunciation.
Soil and plant analysis, C. S. PIPER (New York: Interscience Pubs., 1944, pp.
368-, illus. 19).-This is a photo offset reprint of the publication noted previously
(E. S. R., 90, p. 722).
Semimicrodetermination of the exchange capacity of soils, E. C. CANTINO.
(Univ. Calif.). (Soil Sci., 57 (1944), No. 6, pp. 399-404, illus. 2).-A 1-gm. sample
of the soil is placed in a 3- by 16-cm. centrifuge tube containing 25 cc. of ammonium
acetate. The mixture is thoroughly agitated by hand to suspend temporarily as
much of the soil as possible in the liquid phase. It is digested for 25 min. in a water
bath maintained between 60 and 70 C. 'The contents are then centrifuged at a force
of 104 X gravity for 5 min. The supernatant liquid is decanted and a second 20-cc.
portion of ammonium acetate added. The mixture is agitated, digested for 10 min.,
and centrifuged again. After three such treatments, the presence or absence of calcium
is ascertained in the supernatant liquid. The digestion and centrifugation
process described is continued until calcium (or other indicator ion) ceases to appear
in the liquid phase. The soil is then digested for several minutes with a final 10 cc.
of reagent and centrifuged. Generally, the exchange complex is saturated with
ammonia after three to five centrifugations have been completed. Ten cc. of methyl
alcohol (pH adjusted to 7 with NH5OH or HC1) are added to the soil residue. The
mixture is digested for 5 min. in a water bath maintained at 45, followed by cen1
The publications abstracted in these columns are seldom available for distribution by the Office
of Experiment Stations. In general, application should be made to the Office of Information of the
U. S. Department of Agriculture, Washington 25, D. C., for publications of the Department; to
the directors of the State agricultural experiment stations, as listed on page 3 of the cover of this
issue, for publications of the several experiment stations; and to publishers of books and journals for
material issued by them. Microfilms and photostatic copies, the latter legible without magnifying
equipment, may be purchased from the Library, U. S. Department of Agriculture, Washington 25,
D. C. Rates and other details are explained in a previous issue (E. S. R., 87, p. 324).
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