336 BULLETIN 312 



six times the volume of the seed. Stir the mixture thoroughly with 

 a stirring rod until all seeds are completely coated with the acid. Allow to 

 stand for 15 to 45 minutes at ordinary room temperature, the longer 

 time being necessary if the percentage of hard seed is high. At the end 

 of this time allow water from a faucet to run into the vial or test tube 

 until it is nearly full, then quickly pour the entire contents into the strainer 

 and wash quickly with water. (If this method is followed it should be 

 done over a porcelain or other acid-resistant sink, and the waste acid 

 washed away with water.) Wash for five minutes in running water or 

 until the seed is entirely free from acid. The seed may be planted 

 immediately or it may be allowed to dry before planting, the former 

 process being preferable for small lots of seed. 



For seed in large quantities of one half peck or more: 



For larger amounts of seed for sowing in fields the following modifi- 

 cations make the above method applicable: 



A stone jar of two or three gallons capacity, or larger, may be used as 

 a receptacle in which to mix the seed and the acid, and a wooden or iron 

 stick (a broomstick is satisfactory) may be used for stirring. . The acid 

 may be washed off by pouring the seed and acid into a wooden box whose 

 bottom has been replaced by a screen of proper mesh. After draining 

 a few minutes, water should be poured over the seed, in large amounts 

 at first in order to prevent heating, and this process should be continued 

 until all acid is washed away. For larger amounts of seed, which is to be 

 sown in a seeder, it will be necessary to allow the seed to dry before sow- 

 ing. This may be accomplished by spreading it out on a floor, or other 

 suitable place, in a thin layer. 



LITERATURE 



1. Rostrup, O. Report of the Danish Seed Control for 1896-97. Pp. 37. 



Copenhagen. 1898. (Review E. S. R. 10: 53-54.) 



2. Todaro, F. Azione dell'acido solforico concentrate su alcuni semi, 



e in particolare sopra i semi duri delle Leguminose. Staz. Sper. 

 Agr. Ital., 34: 613:689. No. 7. 1901. (Review E. S. R. 13: 

 7S4-7S5-) 



3. Thornber, J. J. Arizona Station Report, 1904: 489-493. 



4. Schneider-Orelli, O. The Resistance of Medicago Seed to High 



Temperatures. Flora 100: 305-311. No. 2. 1910. (Review E. 

 S. R. 24: 231.) 



5. Bolley, H. L. The Agricultural Value of Hard Seeds in Alfalfa and 



Clover Seeds. Paper read before the Association of Official Seed 

 Analysts. 1910. 



