Oct., 1922] TURNER EFFECTS OF CERTAIN MINERAL SALTS 
421 
nitrate, potassium nitrate, and magnesium nitrate as the source of nitrates; 
monobasic potassium phosphate, magnesium phosphate, and monobasic 
calcium phosphate as the source of phosphates; and magnesium sulphate, 
potassium sulphate, and calcium sulphate as the source of sulphates. The 
basic elements except iron are likewise derived from three different com- 
pounds. This really amounts to a three-salt solution. The following 
scheme will better enable us to visualize the component salts in the solution: 
Ca(N03)2 KNO3 Mg(N03)4 
Ca(H2P04)2 KH2PO4 Mg3(P04)2 
CaS04 K2SO4 MgS04 
Reduction of salts in a horizontal or a vertical direction will enable us to 
vary the anions or cations at will. If a reduced or increased amount of 
nitrates is required in a particular solution, it may be secured by taking re- 
duced or increased proportionate amounts of the three nitrate salts; while 
this will slightly reduce or increase, as the case may be, the total quantities 
of magnesium, calcium, and potassium in the solutions, the reductions or 
increments, being only a small part of the total amounts, would not greatly 
affect the total balance of these cations in the solution.^ Care was observed 
always as to the total concentration. 
In the first experiment, three solutions were employed; in these the 
quantities of nitrates were varied while the other components were kept 
approximately constant. This, of course, made a difference in the total 
concentration of the solutions, but the variations are well within limits 
which have been shown experimentally to be without significant efifect 
upon yield. 
The solution with the lowest nitrate concentration was designated 
Solution I; that next in order of concentration of nitrates. Solution II; and 
the one with the highest concentration of nitrates. Solution III. They 
had the following salt compositions: 
Sol. I 
(Low N) 
Sol. II 
(Medium N) 
Sol. Ill 
(High N) 
KN0.3 
KH2P04 
K2S04 
Ca(N03)2 
Ca(H2P04) 
CaS04 
Mg(N03)2 
Mg3(P04)2 
MgS04 
H20 
.025 g. 
.1 
.1 
.025 
.1 
.1 
.025 
.1 
.1 
1,000 cc. 
•25 g- 
.1 
.1 
•25 
.1 
.1 
•25 
.1 
.1 
1,000 cc. 
•50 g- 
.1 
.1 
•50 
.1 
.1 
•50 
1,000 cc. 
Total salts per liter 
•675 g- 
1-35 g- 
2.1 g. 
^ This method of varying the salt components was suggested by Dr. Otis F. Curtis 
and was found to be a much more practical way of varying the amounts of, or omitting, 
an element than the usual practice of substitution in which entirely new elements are often 
introduced or the concentration of certain of the other ions already present is greatly 
altered. 
