195 
O' Brien . — The Proteids of Wheat. 
is afforded by the fact that the amount obtainable of any 
one of them may be made to vary by varying treatment of 
the gluten. 
a. Zymom .— Zymom is most simply prepared by boiling 
gluten in alcohol ; but thus obtained it may have passed into 
the coagulated state, and may moreover contain some of the 
glian which has become coagulated. To avoid this it may be 
prepared by carefully washing gluten at ordinary temperatures 
with alcohol : at first of about 6o°/ o , then of 6 f/ o , and so on 
up to 90°/ o (Ritthausen). Even as thus obtained, its solubility 
is less than that of gluten as a whole ; especially is it less 
soluble in acids, which points to its having undergone some 
change in the process of separation. The estimates given of 
its amount differ : Ritthausen states it as 28*3°/ o of pure, dry 
gluten ; Von Bibra as Jo°/ o of crude gluten, probably corre- 
sponding to about 6 2°/ 0 of pure, dry gluten ; Taddei’s zymom 
represents one-third of the volume of moist gluten. The 
following estimates agree on the whole with those of Von Bibra. 
The process of exhaustion with alcohol was effected by means 
of the condensing apparatus to be described later, the gluten 
being cut into small pieces. Moist gluten was used, so that 
the proportion of dry gluten has had to be calculated, either 
by taking this as present to the extent of 44%, or by 
determining it separately for the gluten in question. Zymom 
prepared as above would contain all the solid impurities of 
crude gluten, so that about 20°/ o has been allowed for this to 
give the results of the third column — the calculated proportion 
of zymom in pure dry gluten. 
Percentage of Zymom in Gluten. 
1. Moist. 
28-9 
32.14 
35-26 
27-5 
2. Crude dry. 
64-89 
7o-3i 
78-35 
64.94 
3. Pure dry. 
56 
64 
74 
56 
The results vary considerably ; roughly speaking, about 7o°/ o 
of crude, 5o-6o°/ o of pure dry gluten, is insoluble in alcohol, 
i. e. consists of zymom. Differences to the above extent 
might have been expected, because of the difficulty of weighing 
