O'Brien . — The Proteids of Wheat. 217 
network. The membrane persists, sometimes in a contracted 
form, which can, however, be made to resume its former 
dimensions by the use of caustic potash. A 20°/ o salt-solution 
at first attacks the grains more readily, but it cannot cause 
complete dissolution ; whilst in a weaker solution (1-5%) 
the process is regular and frequently takes place from within, 
when the core itself appears as a hollow sphere. Statements 
as to the insolubility of these aleuron- grains in water and 
salt-solutions seem to be due to the persistence of the peri- 
pheral layer or membrane, which may be mistaken for the 
intact grain. Confirmation of their having passed into 
solution is afforded by the fact that a drop of the water 
or salt-solution employed gave a calcium reaction, forming 
insoluble crystals of calcium oxalate when evaporated on 
a slide with an ammoniacal solution of ammonium oxalate 
and chloride. I did not think it necessary to test similarly 
in each case for magnesium and phosphates. 
In Alcohol (S°°/ 0 ) the core of the aleuron-grain seems to 
dissolve from within, somewhat more rapidly than in water. 
The effect of absolute alcohol (2 months) is to render it insoluble 
in water and salt-solution, and only soluble in potash on 
standing for twelve hours. 
Ammonium chloride dissolves the core at once from without, 
and the membrane also rapidly dissolves, though it is some- 
times the last thing to disappear. 
Sodium phosphate (Na 2 HP 0 4 ) dissolves both core and 
membrane, thus showing that the former is not of the nature 
of a crystalloid, this being left untouched by this reagent 
(Ltidtke 12 ). If this salt is added in ammoniacal solution of 
ammonium chloride, crystals of ammonium and magnesium 
phosphate prove the presence of magnesium. 
Caustic potash (i°/ o ) acts violently on the cell-protoplasm, 
which swells up and sets free the grains. The core slowly 
dissolves, usually from without ; a small central mass may 
often persist for some time, but it finally disappears. The 
membrane becomes transparent, but does not dissolve, as is 
evident after addition of water or on neutralisation, especially % 
