134 SOILS AND CROPS OF THE FARM. 



than the normal kernels of wheat they make the head 

 somewhat larger in diameter, and the kernels can be 

 seen more plainly. The kernels are filled with a 

 rather dull, brownish powder, which has a very dis- 

 agreeable and penetrating odor. 



The disease is spread by the use of smutted seed 

 and is to be prevented by sowing on clean ground 

 and with seed free from smut spores. 



The infected seed may be practically if not entirely 

 freed from the disease. The methods used consist in 

 soaking the seed in certain solutions, or simply in hot 

 water. The most common solutions are a saturated 

 solution of common salt and a five per cent solution 

 of copper sulphate. The wheat should be placed in 

 sacks or baskets and these put into the solution and 

 allowed to stand twenty-four to thirty-six hours, when 

 the wheat should be spread out to dry. 



More recently the Danish investigator, Jensen, has 

 introduced the method of soaking the wheat in water 

 at the temperature of from 127 to 133 degrees 

 Fahrenheit for five minutes. American experimenters 

 recommend fifteen minutes. 



