1920] 
DUGGAR—INSOLUBLE SALTS IN BALANCED SOLUTIONS 321 
tures where the magnesium salt is the more soluble, Nos. 8-13, 
the more favorable action of ferric citrate as contrasted with 
the soluble ferric phosphate and FePO, in these cultures with 
wheat is clearly shown. With the exceptions noted the favor- 
able influence of soluble ferric phosphate in the solution is evi- 
dent, especially in Nos. 2 and 6, as also, of course, in solution B. 
The Tottingham solution was exceeded by 5 combinations. 
The Shive solution, solution A (No. 15) was unsatisfactory in 
this series, since after being set up it was found that the acidity 
was much higher than usual. In these experiments, however, 
no recrystallization of the salts employed was carried out and 
no corrections for acidity were made. 
The six cultures giving the higher yields (Nos. 2, 6, 9, 13, 16, 
and 17) were all green and healthy in appearance. Cultures 
3 and 5, without KNO,, were characterized by marked attenua- 
tion; No. 14 exhibited excessive greening; and Nos. 7 and 15 
were abnormally stocky in general appearance. 
As stated previously, the experiments shown in table mr and 
in fig. 4 were also obtained at Carmel. The experiments were 
set up on July 10, using wheat as a test plant and employing 
quart jars as containers. For cultures 1-20 the same stock 
solutions of KNO, and MgSO, as described for table 11 were 
used. The results are not in entire agreement with those given 
in table 11. This may be accounted for in part by the use of the 
larger containers and also in part by differences in weather 
conditions. During the progress of the experiments here dis- 
cussed, there were several days of comparatively warm weather 
without fog, inducing high evaporation rates. It is well to note 
also that a slight mishap to culture 2, which was found upset 
one morning, may be responsible in some measure for the low 
yield of this culture. 
Renewals of the solutions in the control cultures (Nos. 21- 
23) were made about every 10 days. Additional amounts of 
KNO,, 20 cc. in the case of all cultures in column *'1" and 10 cc. 
in the case of column “11,” were added on July 24 and August 6. 
No additional MgSO, was added to the cultures receiving this 
salt until August 6, when 10 cc. were given each of those receiv- 
ing this salt in column “1,” and 5 cc. for similar cultures in col- 
umn “m.” With the larger amount of nitrate employed, cul- 
