198 O'Brien. — The Proteids of Wheat. 
tenacity of gluten ; but after being washed, and dried even at 
ico° C., it seems to me to possess a considerable amount of 
elasticity, and though as precipitated from a solution which 
has boiled for some time it is less sticky, yet it still coheres on 
drying. 
An alcoholic extract of gluten (i. e. a solution of glian), even 
when perfectly clear, may become cloudy on standing in the 
cold ; on heating, the precipitate thus formed disappears, to 
reappear on cooling : hence myxon, not originally present, 
has formed on standing. This process may be repeated 
several times, the myxon precipitated each time on cooling 
being filtered off, more is formed on standing. It seems 
impossible, even by cooling to o° C., to separate between the 
part which is soluble in the cold in alcohol and that which is 
not, viz. myxon. Prolonged boiling, too, even when the 
solution is kept at the strength of about 8o°/ o alcohol, 
converts more and more of the glian into myxon : this is 
not a case of ordinary coagulation, which takes place most 
readily when there is a large excess of water. All this surely 
points, not to the definite presence of myxon as a constituent 
of gluten, but to a gradual change in the solubility of the 
proteid (glian) at first soluble in alcohol : for if the precipitate 
first described were merely due to loss of alcohol by evapora- 
tion, it should disappear on replacing the loss by addition of 
alcohol, but this is not the case ; again, if the precipitate on 
cooling is simply due to change of temperature it should 
disappear on warming, but this is only partially the case. 
More and more glian is converted into myxon, and the 
myxon finally becomes coagulated, and no longer capable 
of dissolving even by means of heat. The first part of the 
change, however, i. e. into myxon, is not coagulation, for 
myxon is still soluble in dilute potash (\5°/J, although with 
its loss of solubility in alcohol in the cold it has lost likewise 
its solubility in acetic acid. 
I must, however, admit that I did not succeed in making 
all the glian pass over into the myxon form, even by keeping 
it boiling for some hours each day for more than a week. 
