Jacques Loeb 539 
When we treat gelatin first with m/8 NaCl and then with dilute 
solutions. of salts of other monovalent cations the results should 
be essentially the same as if we treated the gelatin with solutions 
of NaCl, since a compound gelatin-Na should exchange its metal 
with Li or K or NH, without essential molecular alteration. 
Hence the results should remain practically the same if a treat- 
ment with mM/8 NaCl is followed by solutions of NaCl or of LiCl 
or KCl. This is true, as Table III shows. 
TABLE III. 
Additional swelling of powdered gelatin perfused twice with 25 cc. 
M/8 NaCl and three times with 25 cc. of the fo!lowing solutions. 
elel/ala/8/8/s/8]e/e]8]e 
is eee sale ee) tia ee | 
fi A ee l 1.5) 3.5) 6 {10.5)15 |24.5/84.5/44.5/52 |53.5/57.5 
ie) rae ia 1 Ds 2.5} 6.65/11.5/16 |24 {33 138.5144 |46.5/53.5 
Pd P Ol it Ae ae 2 2 2 5 1138 |23 _|22.5/39.5/48 147 56 
tO G ae ee ee 3 0 2 2.5) 3.0110 |19.5/30.5/45.5/51 [51 |60 
eh tO he ] 15-075173701 6-511 120-129. 140.5142 915075154.5 
CNEL iso @ its, 4: Pes i. 2 3 67112. 418: 126) 1420 50. (458 1538 
AC AONALS LON) 4 fants 1 i) 1.5) 3.5) 7.5/17 122.5125 {33.5148 (46.5155 
(NH,4)2 oxalate....| 0 1 1 2.5) 5 |11.5)22.5127 |36.5)48.5/49 [54 
Koitartrates. so... 0 0 Poominoiet) 113.7119) YQ8: 137 142°" 146.2153 
(NH,)2 tartrate...| 2 Hage Hottie’ “1625122 2135. 5143, 5149-5152 155 
| 
For the chlorides the swelling becomes noticeable at a dilution 
of m/64, for the sulfates, oxalates, and tartrates at nearly twice 
the dilution; namely, about M/128. Only Li,SO, is an apparent 
exception for reasons still to be investigated. 
It was shown by special controls that if we first treat powdered 
gelatin with m/8 NaeSO, and follow this by weaker concentra- 
tions of NazSO, we get the same critical value for the com- 
mencement of swelling as when we first treat the gelatin with 
m/8 NaCl and follow this with weaker concentrations of Na2SOu,; 
namely, M/128. m/8 LiCl followed by different concentrations 
of LiCl gives the same critical value for the commencement of 
swelling as M/8 NaCl followed by different concentrations of 
Dig 
If the anion has a distinct effect it must show itself in com- 
