Abstract
Previous work in this laboratory 1 led us to conclude that proteins cannot be the essential cause of animal electricity. We then investigated the relation of salt concentration to electromotive forces which is characteristic for tissues. This seemed particularly important in relation to the recent work of Mond. 2
Uninjured green plants show the greatest electromotive effect of the concentration, and exhibit also a striking regularity. 3 With animal organs, such as excised muscle, etc., this effect is much smaller and variable owing to unknown conditions, but it is almost always in the same direction, viz., the dilute solution is on the positive side. Mond, 2 working in Höber's laboratory, has tried to match this effect of concentration on tissue with gelatin; he observed + 1/1 KCl // gelatin (acid or neutral) // 1/512 KCl—0.06 volt.
It is clearly seen that the direction of e. m. f.∗ is opposite to that of almost any tissue. With alkali added to gelatin (amount not given) Mond observed,—1/1 KCL//gelatin (alkalin)//1/512 KCl +0.02 volt This is in the same direction as tissue, but too small, since the uninjured plants (used in place of gelatin) produce an e. m. f. four to five times as large in this cell arrangement. It is true that most tissues exhibit a small electromotive effect of concentration, and some of them none at all. It is possible, therefore, to find some tissue which will resemble Mond's alkaline gelatin cell, however small its e. m. f. is. But. it should be remembered that the number of substances which exhibit some effect of concentration is almost unlimited. This is evident from many former investigations. According to R. Beutner3 water immiscible organic liquids will produce electromotive forces of 0.03 to 0.03 volt when used as central conductors between 1/10 and 1/1000 mol. KCl solutions. All these forces are in the same direction as Mond's alkaline gelatin cell (or tissues).
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