Full resolution (JPEG) - On this page / på denna sida - I. General and Physico-chemical - V. Ions and Salt Action
<< prev. page << föreg. sida << >> nästa sida >> next page >>
Below is the raw OCR text
from the above scanned image.
Do you see an error? Proofread the page now!
Här nedan syns maskintolkade texten från faksimilbilden ovan.
Ser du något fel? Korrekturläs sidan nu!
This page has never been proofread. / Denna sida har aldrig korrekturlästs.
IONS AND SALT ACTION. 73
0.9-1 per cent, CaCl2 0.02-0.024 per cent, KC1 0.02-0.042 per cent,
XaHCO:j 0.01-0.03 per cent. Each of the salts NaCl, CaCl2 and KC1
individually has a poisonous action upon the organ but this action is
counteracted by the presence of the two other salts (antagonistic salt
action).
This neutralizing action of salts has been studied during recent
years especially by J. Loeb and his collaborators. As general results
it has been found that the most favorable quantity relations of the
three salts NaCl, KC1 and CaCk for the maintenance of life is the same
as exists in blood. Especially interesting are the experiments with the
Fundulus heteroclitus, a genus of killifish. This fish, it is remarkable, can
also live in distilled water and is therefore within wide limits, not depend-
ent upon the osmotic pressure of the surrounding medium. For this
reason it is specially suited for the study of the poisonous action of salts
or mixture of salts. KC1 in concentrations in which it exists in sea water
acts as a poison upon these fishes, if it is alone in solution. The same
is true for NaCl. On the contrary these fishes live for an indefinite
time in a pure CaCl2 solution in a concentration similar to sea water.
One mol. KC1 can be very nearly de-toxicated by 17 mol. NaCl or by 8^ mol.
Na2S04. \ mol. K2SO4 is just as poisonous as 1 mol. KC1. The toxicity
of the potassium salts is therefore dependent upon the K ions and the
de-toxicating substance on the Na ion. CaCl2 de-toxicates a KC1 solu-
tion even when ^ mol. CaCb to 1 mol. KC1 is present. SrCl2 shows
almost as great a de-toxicating action as CaCk- NaCl in concentra-
tions, in which it occurs in sea-water can only be incompletely de-toxi-
cated by KC1; only by the addition of CaClo can the complete de-
toxication be brought about. The poisonous action of acids upon
Fundulus can be arrested by neutral salts. 1
Fundulus can accommodate
themselves to a rise in temperature; a rise in temperature can be more
easily endured when the concentration of the surrounding medium is raised
at the same time (Loeb and Wasteneys). Can fishes also accommodate
themselves to an abnormal concentration of the surroundings as long
as the rise in concentration takes place gradually? In both cases the
accommodation, according to Loeb,2
depends upon a slow proceeding
process, possibly a tanning of the surface of the animal.
The fertilized eggs of the Fundulus develop, according to Loeb, just
as well in water free from salt as in sea-water. If the fertilized eggs are
placed in a NaCl solution of the same osmotic pressure as the sea-water
^ioch. Zeichr., 31, 450; 32, 155, 308; 33, 480- 489 (1911); 39, 167; 43, 181
(1912).
2
Loeb and Wasteneys, Journ. of exp. Zool., 12, 543 (1913) and Loeb, Bioch.
Zeitschr., 53, 391 (1913).
<< prev. page << föreg. sida << >> nästa sida >> next page >>
