THE EFFECT OF SOME TRIVALENT AND TETRAVALENT 
KATIONS ON PERMEABILITY 
W. J. V. OSTERHOUT 
(WITH SEVEN FIGURES) 
It has been shown’ that there is a remarkable difference between 
monovalent and bivalent kations in their effects on permeability. 
None of the monovalent kations investigated (except H) are able 
to decrease permeability, while all of the bivalent kations investi- 
gated are able to do so to a marked degree. In view of this it 
becomes important to make similar investigations on the effects of 
trivalent and tetravalent kations. 
It is desirable in these investigations to use salts which give 
neutral solutions, since, as has been previously shown,’ both acid 
and alkali affect permeability. For this reason salts of lanthanum 
are especially useful; nitrates of yttrium and cerium were also 
employed, as they likewise give neutral solutions when used as here 
described. Some experiments were made with ferric sulphate and 
with aluminum salts, but these substances have the disadvantage 
of giving acid solutions. 
The salts used were in all cases the purest obtainable and the 
distilled water was prepared with especial care. 
A solution of La,(NO;)s:12 H.O of the conductivity of sea 
water was made by dissolving 31.5 gm. in 297 cc. of distilled water. 
The concentration was about 0.126 M. A lot of tissue which had 
a resistance in sea water of 1350 ohms was transferred to the 
lanthanum solution. The resistance rose rapidly to a maximum 
of 2350 ohms after which it gradually fell. In a second experiment 
the resistance at the start was 880 ohms and the maximum resist- 
ance 1490 ohms. The results are shown in table I and fig. 1. 
* OsteRHOUT, W. J. V., On the decrease of permeability due to certain bivalent 
kations. Bor. Gaz. 59:315-330. figs. 1. 1915- 
?———, Extreme alterations of permeability without injury. Bort. 
59: 242-253. te 4. 1915. 
Botanical Gazette, vol. 59] [464 
Gaz. 
