EXPERIMENTAL. 



87 



temperature rose to 20 . The preparation, 99, obtained by neutralizing the 

 solution with hydrochloric acid contained the same amount of nitrogen as 

 preparation 98, from which it is evident that prolonged solution in dilute 

 potassium hydroxide solution caused no loss of nitrogen. 



Preparations 98, 99, and 100. 



Another preparation of this substance (preparation 100) was made by 

 completely extracting 200 grams of "patent flour" (from spring wheat) 

 with large quantities of alcohol of 0.90 sp. gr. The flour was then washed 

 with absolute alcohol and air-dried. The dry material was then powdered 

 and made into a dough with distilled water which had considerable coher- 

 ence, showing that the protein insoluble in alcohol played an important part 

 in its formation. This dough was then washed on a fine hair-sieve under a 

 stream of running water, but no coherent gluten resulted. The washings 

 were then allowed to settle, and the sediment, after decanting the solution, 

 was treated with 0.2 per cent potassium-hydroxide water. The solution so 

 obtained, after standing over night, was decanted from the sediment and 

 precipitated with o. 2 per cent hydrochloric acid and the separated protein 

 allowed to settle. The solution was then decanted, the precipitate dissolved 

 in 0.2 per cent potassium-hydroxide water, and filtered clear in the ice-box. 

 The filtered solution was then precipitated and the separated substance 

 treated in the usual manner. This preparation, 100, contained nitrogen, as 

 shown in the above table. 



In order to learn whether any change in the protein occurred in conse- 

 quence of contact with aqueous solutions before extracting with potassium- 

 hydroxide water, the following experiment was made : 



1000 grams of "straight flour" from spring wheat were repeatedly ex- 

 tracted with alcohol of 0.90 sp. gr., and after removing everything soluble 

 in that liquid the alcohol was squeezed out as completely as possible in a 

 screw-press and the residue extracted with 0.2 per cent potassium-hydroxide 

 water. It was found impossible to separate the solution from the undis- 

 solved portion of the meal, either by filtration or subsidence, on account of 

 the presence of gummy matter. An equal volume of alcohol of sp. gr. 0.820 



