420 
R. P. WODEHOUSE 
If the filtrate be faintly acidulated and boiled the leucosin is coagulated 
and forms a fiocculent precipitate which can be removed by filtration. 
The proteose, which now remains in solution, can best be obtained 
by reducing the volume by boiling on the water bath and then dialyzing 
against 95 percent alcohol when it appears in the form of a white 
precipitate which can be washed in alcohol and ether and dried over 
sulphuric acid giving a white powder. When prepared in this manner 
it is perfectly soluble in water or o.oi M KOH, giving a clear solution. 
The globulin precipitated by dialysis from 10 percent NaCl solution 
is largely insoluble when treated a second time with 10 percent NaCl. 
For this reason this method cannot be used advantageously for the 
preparation of globulin. It was found best to follow the method of 
first saturating the 10 percent NaCl extract with ammonium sulphate 
thereby throwing out of solution all of the proteins together. This 
precipitate can then be dissolved in 5 percent NaCl and the solution 
dialyzed free from CI and SO4 when the globulin is thrown out of 
solution in spheroids or imperfect crystals which can be separated 
from the solution by centrifugalizing. Globulin thus prepared can 
nearly all be redissolved in 5 percent NaCl and precipitated again 
by dialysis. In making the globulin preparations used in this work 
this was done twice in order to purify the preparations. It was then 
washed in water, 95 percent alcohol, absolute alcohol and ether and 
dried over sulphuric acid under diminished pressure. This preparation 
is completely soluble in 10 percent NaCl or weak alkali. It appears in 
more or less regular spheroids or imperfect crystals, so it can be con- 
sidered to be reasonably pure. 
Leucosin is very difficult to separate from proteose without coagu- 
lation, therefore no attempt was made to prepare it entirely free from 
proteose. The leucosin used in these experiments was prepared as 
follows: The NaCl extract, after the salt and globulin had been re- 
moved by dialysis was saturated with ammonium sulphate and the 
proteins thereby precipitated were filtered out and pressed as dry as 
possible between filter paper and redissolved in a small amount of 
water, in which they proved to be almost completely soluble. This 
solution was then dialyzed until free from the remaining ammonium 
sulphate, or until it failed to give a precipitate with barium chloride. 
This caused the production of a very small amount of an insoluble 
protean which was filtered out. The solution was tfen dialyzed 
against 95 percent alcohol until further reduced in vjlume. This 
