i6o 
JOHN W. SHIVE 
proportions of the three salts giving the greatest dry weight of tops. 
These results are expressed in the tabulated form below, with those 
of Tottingham's tests added for comparison. 
Relative Dry Weights of Tops of Wheat and Buckwheat Grown in Various 
Solutions 
Experimenter and Plant 
Four-salt Solution 
Three-salt Solution 
Knop's 
Tottingham's Best for 
Wheat Tops 
Shive's Best (1.75 Atm.) 
(2.50 Atm.) 
(1.75 Atm.) 
(2.50 Atm.) 
(1.75 Atm.) 
For Wheat 
Tops 
For Buck- 
wheat Tops 
Tottingham (wheat) . . 
Shive (wheat) 
Shive (buckwheat) . . . 
1.00 
I.OO 
I.OO , 
I.OO 
I. II 
1. 12 
1. 16 
1. 21 
1.27 
I.6I 
From these results it is clear that the three-salt mixture, with 
proper proportions, is not only eminently suitable for plant growth 
but that it gives a markedly better growth of tops than does either 
Tottingham's or Knop's four-salt solution, at least with a total 
osmotic concentration of 1.75 atmospheres, which is a suitable con- 
centration for general water-culture work. 
The Laboratory of Plant Physiology, 
Johns Hopkins University. 
4 
