226 WILLIAM EUGENE PICKLER 



As soon as a container attained a constant weight, a weighed 

 amount of barley grains was removed and rapidly dried. The 

 drying in this case took place in a drier especially constructed 

 for the purpose. By means of a blower, heated air was driven 

 over wire pans which were arranged in tiers and covered with a 

 large tubulated bell-jar. Grains with the largest quantity of 

 water used in these experiments were thoroughly dried in 2 

 hours. 



When the seeds had become thoroughly dried they were 

 ground to a fine powder. Five-tenths of a gram of this ground 

 material was taken from each sample and digested for an hour at 

 50°C. in 50 times its weight of distilled water. During the proc- 

 ess of digestion, the mixture was thoroughly stirred at frequent 

 intervals. The extract obtained was placed in a centrifuge and 

 rapidly rotated for ten minutes in order to remove all suspended 

 materials, especially starch grains. This treatment was found 

 to be necessary, for the amount of starch in the ground material 

 was sufficient to introduce a large error in the results. 



The starch solution 



A 0.2% solution of soluble starch was used in all of the deter- 

 minations for diastase. This was prepared by dissolving an 

 accurately weighed amount of Lintner's soluble starch in 

 boiling distilled water. A fresh solution was made for each 

 determination. 



Diastase activity 



The diastase activity (Abderhalden 1910), (Oppenheimer 

 1911) of the ground barley was determined by adding 4 cc. of 

 the barley extract to 20 cc. of the starch solution. The mixture 

 was placed in a 50 cc. flask which was then immersed in the bath 

 until only a small part of the neck extended above the water. 

 At intervals, 2 cc. of this solution were removed from the flask 

 and added to an equal quantity of distilled water in a test tube. 

 It was rapidly brought to boiling and allowed to cool to room 

 temperature. Each tube was then tested with 3 drops of a 0.1 



