[Vor. 4 
166 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
rials vary so greatly in water content that if any satisfactory 
standard is adopted it is necessarily on the dry weight basis. 
Accordingly, for the plant products utilized in preparing the 
decoctions employed in this work, the quantities required, as 
calculated from the data in convenient handbooks,’ are as 
follows: green (string) beans 391.5 grams; corn meal 58.6 
grams; fresh turnips 524.1 grams; sugar beets 370.4 grams; 
prunes (dried, exclusive of seed) 70.7; and potatoes 236.8. 
It is obvious that such plant products will vary more or 
less in water content depending upon the variety and the 
season, but this is relatively a minor consideration. 
In each case the full weight of material required was cut 
up into small pieces (not more than 1 em. in length or 
diameter), added to 1 liter of water, autoclaved at 15 pounds 
pressure for 1 hour, filtered hot, and made up to the full 
quantity, if there had been loss of water. It was determined 
to use the natural (or native) decoction in each сазе, and also 
each one amended as indicated in the series below, these also 
corresponding to Ше 7 columns (I-VII) of nutrient media in 
table 1. 
Natural decoction, full strength. 
П Natural decoction, full strength standardized in reaction 
to + 15 Fuller’s scale. 
ПІ One-half strength standardized decoction + 13.68% 
(.4N) cane sugar. 
ТУ One-half strength standardized decoction + 3.42% 
(АХ) cane sugar. 
V One-half strength standardized decoction + 13.68% 
cane sugar + 1% KNO; + .5% KH2POsg. 
VI One-half strength standardized decoction + 13.68% 
cane sugar + 1% KNOs. 
ҮП One-half strength standardized decoction + 13.68% 
cane sugar + .5% КНРО,. 
A part of each decoction was therefore set aside to be 
used in natural condition while the remainder was titrated, 
m 
! Jen , E. H., and Winton, A. L. A ә” = pU of American 
feeding sur U. 8. De ept. Agr., Exp. Sta. Bul. 
i Chemische Zusammensetzung der bacs Nahrungs- und 
Genussmittel. Berlin, 1889. 
