26 THE PROTEINS OF THE WHEAT KERNEL. 



separate the phosphorus from our extract in order to determine, if possible, 

 the relation of the preparations free from phosphorus to those which con- 

 tained much phosphorus. 



2000 grams of meal were treated with 6 liters of distilled water, and the 

 extract (4 liters) was squeezed out as completely as possible in a press. 



As a preliminary experiment 100 cc. of this clear, filtered extract were 

 made faintly alkaline to phenolphthalein, with about 40 cc. of decinormal 

 potassium-hydroxide solution. To insure a sufficient quantity 20 cc. more 

 of alkali were added, and thereupon a little calcium chloride, which gave a 

 precipitate that seemed to partly dissolve on adding sodium chloride. The 

 undissolved part, when washed with dilute sodium-chloride solution, water, 

 and alcohol, and dried, formed 1.7 per cent of the meal, contained about 55 

 per cent of organic matter, and left 45 per cent of ash, consisting of tricalcium 

 phosphate. 



To 2000 cc. of the original extract were then added 1350 cc. of a solution 

 containing alkali, equivalent to 1560 cc. decinormal solution, with sodium 

 chloride enough to form 6.5 per cent of the total liquid. To this a solution 

 of calcium chloride was added as long as a precipitate formed, and after 

 standing over night the solution was decanted from the precipitate and filtered 

 clear on a pulp filter. Of the clear filtrate 2200 cc. were made as neutral as 

 possible to litmus by adding 180 cc. of decinormal hydrochloric acid solution. 

 Of the solution thus neutralized 1000 cc., when gradually heated in a 

 water-bath, became turbid at 52 and a considerable coagulum separated 

 at 53. 



After the temperature had been slowly raised to 65 and kept at this point 

 some time, the coagulum was filtered out, washed, and dried as usual, giving 

 preparation 20, weighing 6.4 grams. Another portion of this extract, filtered 

 from the calcium-chloride precipitate, was saturated with ammonium sulphate 

 while still slightly alkaline to litmus, the resulting precipitate filtered out, 

 dissolved in water, its solution filtered clear, and dialyzed. A slight precip- 

 itate formed on dialysis, which was removed by filtering and the solution 

 heated in a boiling water-bath. The protein thus coagulated weighed 3.07 

 grams, preparation 21. 



To determine what effect the removal of the phosphorized substance thrown 

 out by calcium chloride had upon the precipitation with sodium chloride, we 

 made neutral to litmus a liter of the filtrate from the calcium-chloride precip- 

 itate and then saturated it with sodium chloride. The large precipitate 

 which formed was washed by decantation with water, in which it gradually 

 dissolved, until only an insignificant quantity remained. The similarly ob- 

 tained precipitate from the simple aqueous extract we have shown to be nearly 

 all insoluble in water. 



