600 Wisconsin Academy of Sciences^ Arts, and Letters. 
extraction under the conditions outlined above, when calcul¬ 
ated on the original is as follows: 
Sample 
C 
D 
E 
Soluble in alcohol 
39.58% 
45.73 
20.07 
Crude fiber. The amount of crude fiber was determined 
by the method of digestion for half-hour periods with sul¬ 
phuric acid and sodium hydroxide solutions of specific gravity 
1.25, filtering on tared Gooch crucibles, washing, drying at 
100° C., and ignition. We found that this determination can 
be expedited by completely washing out the alkali with hot water 
after the last digestion and then washing the residue from the 
linen filter with a small volume of hot water into a 100-c.c. 
beaker. After allowing the residue to settle, which takes but 
a short time, the solution is decanted through the Gooch cruci¬ 
ble and then the residue is washed from the beaker with a 
small quantity of water. This procedure permits of the rapid 
filtration of a solution which otherwise invariably clogs the 
filter. 
A close agreement was found between the amounts of crude 
fiber contained in the Crustacea catches, but a rather wide 
variation among the plant catches. The algal catch contains 
less crude fiber than any of this series. The crude fiber con¬ 
tent calculated on a dry basis is as follows: 
Sample 
Crude fiber 
A 
4.58% 
B 
2.61 
C 
5.40 
D 
5.63 
E 
1.30 
154 
3.33 
5138 
2.13 
crude fiber obtained in 
each case was found to contain 
nitrogen. This nitrogen is not part of the proteins inasmuch 
as they are hydrolyzed during the treatment, the products of 
hydrolysis being soluble and going into the filtrate. It must 
be considered as one of the forms of the nitrogen-containing 
