WatTerR ABSORPTION BY MUSCLES AND Soaps 511 
became very marked; after eighteen hours, for example, it 
was found that the muscle kept in an isotonic KCl solution 
had gained from 40 to 50 per cent. in weight; that a 
muscle in a CaCl, solution lost about 20 per cent. in weight; 
that the weight of a muscle in LiCl remained practically 
unchanged; while that in NaCl solution had increased a few 
per cent. in weight. The following gives a summary of 
these results: 
TABLE I 
Changes in weight in the gastrocnemii of frogs kept in solutions equimolecular 
with a 0.7 per cent. NaCl solution. Length of the experiment, 18 hours. An 
increase in weight (expressed in per cent. of the original weight of the muscle) 
is designated by a+; a loss in weight by a —. 
LiCl..... —1¢ NaCl...+62 KCl] ....+45% CaCl... —20% 
LiBr..... —1 NaBr....+ 7 KBr....+41 
Tei sas bces +3 Nal..... +10 KYI...... +45 
The figures given in this table were corroborated by a 
large number of experiments. Variations due to individual 
differences in the muscles and variations in the temperature 
are unavoidable, but the order of magnitude of the results 
obtained was always about the same as those given above. 
Since the difference in the degree of dissociation of the 
potassium and sodium salts is very slight, it is of course ex- 
cluded that differences in osmotic pressure, due to differ- 
ences in the degree of dissociation, should be responsible 
for the results obtained. 
The potassium and sodium salts of other acids, such as 
the sulphates and oxalates, also show these differences, 
though not so markedly. 
Wallace and Cushny believe that only the anions and 
not the cations of salts play a réle in the absorption of 
water from the intestines." If this is true, the absorption 
of liquids by the intestine must be governed by entirely 
different laws from those which govern the absorption of 
1 WALLACE AND Cusuny, American Journal of Physiology, Vol. I, p. 411. 
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