1915] 
OSTERHOUT—PERMEABILITY 
471 
resistance rose in 30 minutes to goo ohms, and in the course of 2 
hours reached 970 ohms; it then began to fall, and at the end of 
TABLE VI 
ELECTRICAL RESISTANCE OF Laminaria saccharina 
In sea water 
nes Io0oo cc. + 
Time in hours Al.(SO,); 18 H,0 
6. 7 gm. 
In sea water 
LOE Ce Bee aN gd OT 800 
2 age Sea bagless 1100 
On 7628 ok ag 1000 
b Ge | Bech oer ope cn ee 950 
ae A NL Si Bec a 37° 
20.5 hours it was 630 ohms. 
and fig. 4 (p. 469). 
Another lot of tissue which had in 
sea water a resistance of 750 ohms was 
transferred to sea water 1000 cc.+ 
Fe,(SO,), 1 gm. (=0.0025 M). The 
resistance rose in the course of 30 
minutes to 810 ohms; at the end of 1.5 
hours it had fallen to 600 ohms, and it 
continued to fall rapidly after this. The 
solution was acid to litmus, but the 
degree of acidity was not sufficient to 
account for the whole of the effect. The 
results are shown in table V and fig. 5. 
Experiments were made with several 
salts of aluminum, including aluminum 
chloride, aluminum sulphate, ordinary 
alum, and chrome alum, which were 
added in solid form to sea water. All 
of them gave similar results. The solu- 
tions were acid, but the acidity was 
not great enough to account for the 
whole of the effect. The action of these 
salts is illustrated by table VI and 
fig. 6, which show the results obtained 
by adding 6.7 gm. Al,(SO,)3° -18 H,0 to 
The results are shown in table IV 
1100 OHMS 
2 HOURS 
Fic. 6.—Curves of electrical 
resistance of Laminaria sac- 
charina in sea water 1000 
cc.+Al,(SO,);-18 HO 6.7 gm. 
(=o.01 M) (unbroken line), 
and of a control in sea water 
(dotted line). 
