24 THE PROTEINS OF 'THE WHEAT KERNEL. 



with 9 liters of water. The coagulum produced, weighing 62 grams, formed 

 more than 9 per cent of the oil-free germ meal. This is preparation 7. 



Another aqueous extract was heated at 65 until all the protein coagu- 

 lable at this temperature had separated. The coagulum produced, when 

 washed with hot water and alcohol, was dried over sulphuric acid and 

 found to weigh 16.68 grams. The filtrate from this coagulum, heated in a 

 boiling water-bath, yielded a second coagulum which formed preparation 8, 

 weighing 4.9 grams. 



A portion of the extract which yielded preparation 6 was saturated with 

 ammonium sulphate; the resulting precipitate was dissolved as far as possi- 

 ble in water, its solution filtered clear and dialyzed for 4 days. During 

 this time a considerable precipitate formed that, when filtered out, was 

 found to be insoluble in salt solution. The solution, filtered from that sub- 

 stance and dialyzed in running water until nothing more separated, was 

 filtered and heated at 60, which caused a coagulum. This coagulum 

 weighed 7.1 grams and made preparation 9. 



When 2000 cc. of an extract of 650 grams of wheat-germ meal was dia- 

 lyzed 4 days, a dense turbidity formed, due to a globulin, since it dissolved 

 on adding sodium chloride. Passing carbon dioxide gas through the dialyz- 

 ing solution seemed to increase the turbidity, but effected no definite separa- 

 tion. As it was found that 10 cc. of decinormal hydrochloric acid per 100 cc. 

 of the extract caused a separable precipitate, this proportion was added and 

 the resulting flocculent precipitate brought into solution again by adding 

 sodium chloride. The clear solution was then dialyzed for 2 days in run- 

 ning water and filtered from an amorphous precipitate, which was treated as 

 later described on page 44. 



The filtrate from this precipitate was further dialyzed for 3 days more in 

 running water and then, as nothing separated, for 4 days more in alcohol. 

 The precipitate which resulted was dried over sulphuric acid, exhausted 

 with water, in order to remove all uncoagulated proteins, as well as other 

 soluble substances, dehydrated with absolute alcohol, again dried and 

 weighed, yielding 12 grams of preparation 10. 



Another aqueous extract was saturated with pure sodium chloride, the 

 abundant precipitate filtered out, treated with dilute brine, and the resulting 

 solution filtered from a relatively considerable quantity of insoluble matter. 

 This filtrate was saturated with sodium chloride, a second precipitate filtered 

 out, and likewise treated with dilute sodium-chloride solution. The insol- 

 uble portion was removed by filtration and the clear filtrate dialyzed. The 

 small precipitate separated by dialysis when washed and dried, weighed 4.8 

 grams and formed preparation 1 1 . 



