BREAKDOWN OF FRUIT AND VEGETABLE TISSUE DUE TO AN
(WITH TWO FIGURES)
Experiments in electrodialysis involving the use of natural membranes
revealed the interesting fact that the tissues of fruits and vegetables break
down very rapidly when they are the cathode of an electric circuit, but do
so only to a slight degree, if at all, when they are the anode.
An apple resting in a bowl containing a weak salt solution, with one elec-
trode of an electric circuit penetrating it and the other electrode projecting
into the surrounding solution, will "rot" after eighteen to twenty-four
hours if the apple is the cathode or negative pole (fig. 1).
If the apple is
Effect of the negative electrode of a 110-volt direct current on an apple
standing in 0.1 N NaCl for twenty hours. The cross-lined portion is well "rotted" (soft
and dark brown in color); the heavily stippled region is considerably discolored (to
green), and the lightly stippled portion is slightly discolored.
the anode or positive pole, the tissue is little damaged. The foregoing was
the original experiment; it was repeated many times and then duplicated
with other fruits and vegetables, always with the same result, except that
the degree and kind of degeneration of tissue varied with the material.
Particularly striking were the results obtained with the persimmon and
The experimental findings are listed below. The electrodes were of
platinum and the circuit a 110-volt direct current, with an intervening 0.5
ampere electric-light bulb. The surrounding solution was 0.1 N NaCl, and
the length of the run, eighteen to twenty-four hours. The fruit was im-
mersed in the solution one-half to two-thirds of its height. The degree of
acidity of the normal fruit and of the tissues surrounding the respective
poles was obtained by macerating the tissue in a minimum amount of water.
The values, in terms of pH, are given, that of the normal fruit first, the
treated last. The word "rotting" will be used as