193 
O'Brien . — The Proteids of Wheat . 
boiling into even a large quantity of boiling water some of it 
is at once precipitated : nor can it in any way be made to 
dissolve. (2) If an extract of gluten is made with boiling water 
and cooled, the c insoluble phytalbumose ’ appears as a cloudy 
precipitate : this may be readily dissolved in the cold by 
the gradual addition of alcohol to form a dilute alcoholic 
solution. Thus whilst the ‘ phytalbumose ’ is entirely soluble 
in dilute alcohol, glian is only partially soluble in boiling 
water. (3) The following method was employed to determine 
the actual amount of gluten soluble in boiling water and in 
alcohol respectively, i. e. the quantities of ‘ phytalbumose ’ 
and of glian to be obtained. A piece of freshly prepared 
gluten was divided into three parts, each consisting of about 
2 grams. One part was dried, in order to show the proportion 
of gluten in the moist mass. Another part was cut into 
small pieces, exhausted with alcohol, and the residue dried 
and weighed. The third part was likewise cut into small 
pieces ; these were dropped into a large amount of water 
(about 1 litre) at ioo° C., and were almost immediately 
collected on a filter and washed with boiling water till no 
more proteid was extracted. The residue obtained in this 
way could not consist of any part once dissolved and then 
coagulated. The difference between the residue and the 
dry weight of the gluten employed in each case was calculated : 
it represents the amount which had passed into solution 
as glian and phytalbumose respectively. 
Phytalbumose 6- 2 % Glian 26-6 % 
„ 7' 8 4% » 35-o 6 % 
The phytalbumose-solution gives the general proteid re- 
actions, and, as Martin has described, those characteristic 
of an albumose. A part of it [mucin] remains in solution 
even in the cold, and is described, under the name of mucedin, 
by Ritthausen, as one of the essential constituents of gluten. 
But as it cannot be extracted from gluten in the first place 
by water at ordinary temperatures it is probably a secondary 
product resulting from the action of boiling water. Water 
