SOLUTION FOR HIGHER PLANTS 125 



Solutions should be prepared with ammonia-free water 

 and chemically pure salts. 



Dilute lo-c.c. portions of (a), (6), (c), and (d) and i c.c. 

 of (e) in 1000 c.c. of water. If a nitrogen-free medium is 

 desired, omit (a). Plant food solutions should be renewed 

 at regular intervals of about one week each. 



Hopkins and Pettit, Soil Fertility Laboratory Manual, p. 22, 1910. 



Medium 81 

 Solution for Higher Plants 



Potassium nitrate (KNO 3 ) i.oo gm. 



Magnesium sulphate (MgSO 4 4- 7H 2 O) 0.25 gm. 



Calcium sulphate (CaSO 4 + 2H 2 O) 0.25 gm. 



Tricalcium phosphate (Ca 3 (PO4)2) 0.25 gm. 



Ferrous phosphate (Fe 3 (PO 4 )2) 0.25 gm. 



Distilled water. . . 1000.00 c.c. 



This solution is supposed to prevent the growth of algae. 



Crone, G., Stizungsber-Niederrhein. Gesell. Nat. und Heilkunde, Bonn., 

 pp. 167-173, 1902. 



Medium 82 

 Soft Agar for Plants 



For growing plants 0.75 per cent, of agar in mannit solu- 

 tion (see page 108) is very satisfactory. 



Medium 83 

 Solution for Higher Plants 



(a) Monobasic potassium phosphate (KHaPC^).. , i22.5gm.. 

 Distilled water ............... ....... ....... 1000.0 c.c. 



