O' Brien. — The Proteids of Wheat {II). 547 
Thus the proteids of germ and of flour seem to correspond 
so far as the globulins and proteoses are concerned, but in the 
remaining proteid-matter they differ widely — the insoluble 
gluten of the endosperm taking the place of the albumin of 
the germ. Osborne and Vorhees 1 have, however, described 
as an albumin from flour, under the name of leucosin, a 
substance which is apparently the proteid which I have 
classed as a globulin of the myosin-type. As pointed out 
in the postscript to my previous paper, these authors admit 
that it has certain qualities which are exceptional for an 
albumin, inasmuch as it is precipitated by magnesium sulphate 
and coagulates at the low temperature of 52 0 C. But the fact 
that this proteid was not, in their experiments, precipitated 
from saline solution by dialysis, led to its classification by 
them as an albumin. So far, however, as I have been able 
to investigate the point, I have never found the proteid in 
question to behave in this way on dialysis ; and the further 
fact that it is completely precipitated by passing a stream of 
carbonic acid gas through its solution supports the view that 
it is a globulin rather than an albumin. 
Among my dialysis-experiments were the following. (1) A 
watery extract of flour was saturated with magnesium sulphate ; 
the precipitate formed was redissolved, and its solution sub- 
mitted to dialysis. After ten days the liquid in the dialyser, 
when filtered from the precipitated proteid, still contained 
a minute trace of coagulable proteid. Since, however, it did 
not show any sign of coagulation below 6o° C., but only 
as boiling-point was approached, it would seem that this 
coagulable proteid could not be either the myosin-like 
globulin or Osborne’s albumin (leucosin), but was a small 
residue of the vitellin-globulin. (2) In another case an 
extract of flour made with io°/ o sodium chloride solution 
was, in the same way, saturated with magnesium sulphate, 
and the resulting precipitate redissolved as before. After the 
solution had been submitted to dialysis for eleven days in the 
presence of chloroform, and a dense precipitate had been 
1 Connecticut Agricultural Experiment Station, Annual Report, 1893. 
