544. Proteins | 
tion in the usual way, and the salt solution was then removed 
by washing the powdered mass three or four times with distilled 
water. After all the water had run off the mass of gelatin 
was poured into a beaker and completely liquefied by heating for 
about 10 minutes in a water bath of about 40°. This homo- 
geneous liquid mass of gelatin was then put into a bag of collo- 
dion and exposed to the draft of an electric fan for about 24 
hours, when it had lost most of the water. When such blocks 
of gelatin, previously treated with m/8 NaCl and freed from the 
NaCl solution by repeated washings with H.O, were put into 
H.O they showed the same excessive swelling as had been observed 
in the case of the powdered gelatin; while this excessive swelling 
was prevented when the block of gelatin previo treated with 
m/8 NaCl was put back into m/8 NaCl. 
The following is an example. Into each of three cylindrical 
funnels were put 2 gm. of finely powdered Cooper’s unbleached 
gelatin. The gelatin in one funnel (I) was perfused six times in 
succession with distilled water. The second (II) was perfused 
twice with 25 ce. M/8 NaCl, then four times with 25 ce. of dis- 
tilled water; the third (III) was perfused six times with 25 cc. 
M/8 NaCl. After all the water had run out, the weight of the 
first mass of gelatin was 34 gm., that of the second, 59.15 gm., 
and of the third 24.4 gm. The previous treatment with salt in- 
creased the swelling from 32 to 57 gm. Incidentally the reader 
will see that contrary to Hofmeister’s statement the gelatin did not 
swell more when permanently treated with m/8 NaCl than it did 
when permanently treated with H.O, since in the latter case it 
absorbed 32, in the former only 22 gm.—of which part was NaCl.” 
These three lots of gelatin were then put into collodion bags and 
exposed to the fan until their respective masses were 8.4 (1), 7.4 
(II), and 6.05 (III) gm. The three masses of gelatin were then 
liquefied by heating to about 40°C., poured into a flat Petri dish, 
allowed to gelatinize, and then blocks of equal size were stamped 
out of each; the respective weights of the three blocks were 7.6 
(I), 6.04 (II), and 4.19 (III) gm. I and II were put into distilled 
water, III was put into M/8 NaCl. After 24 hours the weighing 
gave the following result: 
12 Ash determination showed that the gelatin contained in this case the 
same proportion of NaCl and water as did the M/8 NaCl solution. 
