WHEAT. 49 



less black and offensive to the smell. Some authors 

 have divided this evil under two different names, re- 

 taining that of smut for one of its modifications, 

 while that of burnt-grain has been given to the other. 

 Mills, in his ' System of Practical Husbandry,' has 

 drawn the line of distinction between the two in the 

 following terms. ' Smut, properly so called, oc- 

 casions a total loss of the infected ears, but as the 

 black powder which it produces is very fine, and the 

 grains of that powder do not adhere together, wind 

 and rain carry them away, so that the husbandman 

 houses little more than the straw, which does not 

 infect the sound grains and scarcely damages their 

 flour. The burnt or carious grains are, on the con- 

 trary, often housed with the sound grain, which they 

 infect with a contagious distemper, at the same time 

 that they render its flour brown, and give it a bad 

 smell.'* The name under which this disease was 

 known by the Romans was uslilago : by the French 

 farmers it is called charbon. 



If a portion of the black powder be first wetted 

 with water, and then put under the microscope, it will 

 be found to consist of myriads of minute globules, 

 transparent, and apparently encompassed by a thin 

 membrane. The cause of this disease has been held 

 by some investigators to originate in the soil wherein 

 the grain is sown; others have attributed it to the 

 growth of a fungus within the ear; while others 

 again have affirmed that it is owing to a diseased 

 state of the seed whence the plant is produced. The 

 result of various experiments conducted with different 

 seeds sown in the same spot, and subjected to the 

 same culture, appear to confirm the correctness of 

 the last hypothesis. 



The average weight of a bushel of wheat is about 

 sixty pounds. Inferior samples seldom weigh less 



* Vol. ii, p. 392. 

 VOL. xv. 5 



