1950 Volume 63 Issue 750 Pages 278-282
A critical study of the occurence of silver nitrate reduction in plant cells was carried out with the following results.
1) Minimum amount of ascorbic acid (reduced form) clearly detectable with acidified silver nitrate solution after GIROUD is 300mg% at 25°C and 150mg% at 40°C (Table 1). At 25°C, 150mg% ascorbic acid is clearly detectable with a si1ver nitrate solution at pH6. 3 (Table 2).
2) As a rule, the more contains the tissue ascorbic acid (reduced form), the more markedly occurs the reduction of silver nitrate. But this relation does not hold good in some cases (Table 4).
3) In most cases, chloroplasts remain colourless when a tissue is treated with acidified silver nitrate solution after GIROUD in darkness.
4) When the tissue treated with the acidified silver nitrate solution is immersed in ordinary alcohol, the alcohol causes a secondary blackening of chloroplasts.