206 O' Brien . — The Proteids of Wheat. 
present in the proteid as thus collected, and may be removed 
by ether: but the amounts given usually represent the crude 
albuminate (dried at ioo°C). Three separate amounts of the 
flour used for gluten-estimation, each weighing 3 grams, gave 
albuminate representing 8*i8%, 8*85%, 8-025% respectively; 
a fourth amount of 5 grams yielded 8-13%: average 8-29%. 
A similar amount (8*358%) was obtained from flour which 
had been kept for some time at ioo° C. 
In what form the albuminate exists in flour it is impossible 
to say, for no * mother-substance ’ has yet been extracted ; 
manifestly globulin is not the precursor, for it could then 
be extracted by salt-solution. Perhaps the suggestion 39 of 
a ‘ mother-substance ’ in oats, antecedent to globulin, may 
here be applicable — a substance whence, according to the 
conditions of hydration, gluten or an albuminate may be 
formed. 
D. Relation between Gluten and the Albuminate. 
The question arises, what is the relation between the glian 
of gluten and the albuminate of flour ? Are they identical ? 
Obviously they are alike, in the first place, as regards their 
solubility in alcohol : and just as the solubility of glian in this 
has been shown to vary, so that of the albuminate may be 
made to vary in the same way. 
If a solution of albuminate in 75% alcohol be precipitated 
with water and allowed to stand for some time, the character 
of the albuminate left on evaporation is found to be changed : 
as already mentioned, it is less sticky, more tough and tena- 
cious, and in physical properties resembles gluten. The 
residue obtained by the evaporation of an alcoholic solution 
may be treated with water with the same result. The sub- 
stance thus obtained behaves towards alcohol in the same way 
as does gluten : it is no longer all soluble, and from the 
extract made with hot alcohol a precipitate is obtained on 
cooling. That is, zymom and myxon are formed from it ; 
and a substance soluble in water (mucin) may be obtained in 
