12 3456 7 89 
Fig. 2. Cultures 1,2, 3, Fe 2 (S0 4 )3, 50 mg. Fe per liter. Cultures 4, 5, 6, Fe 2 (S 0 4 ) 3 , 
10 mg. Fe per liter. Cultures 7, 8, 9, Fe 2 (S0 4 )3, 2 mg. Fe per liter. 
Fig. 3. Cultures 1, 2, ferric citrate, 10 mg. Fe per liter. Cultures 3, 4, Fe 2 (S0 4 )3, 10 
mg. Fe per liter. Cultures 5, 6, Fe S 0 4 , 10 mg. Fe per liter. Cultures 7, 8, Fe P 0 4 , 10 mg- 
Fe per liter. 
123 4567 89 
Fig. 4. Cultures 1, 2, 3, ferric citrate, 50 mg. Fe per liter. Cultures 4, 5, 6, ferric 
citrate, 10 mg. Fe per liter. Cultures 7, 8, 9, ferric citrate, 2 mg. Fe per liter. 
