80 THE BOTANICAL MAGAZINE. [Vol. xxxiv. No. 402. 



the basis of the five potential ions included. Table I, column 1, shows 

 the six solution types, as characterized by their component salts. 



The total volume-molecular concentration of all salts taken together 

 (always 0.015 gram-molecule per liter, as has been said) was con- 

 sidered as divided into seven equal parts, and then fifteen different 

 solutions for any type were so prepared as to apportion the seven 

 units (a unit was 0.00214 gram-molecule in every case, being one- 

 seventh of 0.015 gram-molecule) among the three salts in all possible 

 ways. Table I shows that all six types of solution were alike in that 

 each contained a nitrate salt, a di-hydrogen-phosphate salt and a 

 sulphate salt. The cation proportions differed from type to type but 

 the anion proportions were the same in the corresponding solutions of 

 all types. Of course it is to be noted that, on account of the valences, 

 the S0 4 -unit is S0 4 but that the other two anion units are double, 

 being (N0 3 ) 2 and (H 2 P0 4 ) 2 . 



The solution designations in table I refer to the salt proportions 

 and to the triangular diagram mentioned above (see also fig. 1) ; the 

 number following the letter R (for "row ") denotes the number of 

 sevenths (of the total molecular concentration) due to the nitrate salt 

 (N0 3 ) 2 , the number following the letter S (for " solution ") denotes the 

 number of sevenths due to the di-hydrogen-phosphate salt (H 2 P0 4 ) 2 , 

 and the number of sevenths due to the sulphate salt (S0 4 ) is found by 

 subtracting both of the preceding numbers from seven. Thus, solution 

 R2S3 had 2 sevenths of its total volume-molecular concentration due 

 to tjie (N0 3 ) 2 -salt, 3 sevenths due to the (H 2 P0 4 ) 2 -salt, and 2 sevenths 

 due to the S0 4 -salt. This interpretation applies to solution R2S3 in 

 every one of the six types. The six types are distinguished by letters 

 (A, B, etc.), and the type of any given solution is indicated by placing 

 the type letter before the salt- proportion formula ; thus BR2S3 denotes 

 a solution (see table I) made up of: Mg(N0 3 ) 2 , 2 sevenths ; Ca(H 2 P0 4 } 2 , 

 3 sevenths ; and CaS04, 2 sevenths. 



Table I. 



Showing the six different solution types and the fifteen different sets 

 of salt proportions of the solutions studied, together with the score 

 values for each solution by each of five different growth criteria, and 

 also the generalized or average score values (representing the com- 

 bination of all five criteria) for each solution. 



