DISEASES " CLOYER SICKNESS." 115 



and lime as constituents of our clover soils, no chemical 

 deductions could be drawn as to the cause of failure or 

 success ; neither did an investigation into the organic coin- 

 position of the soils examined give any additional infor- 

 mation. Long practice has shown that the application of 

 gypsum is generally followed by beneficial results. Sul- 

 phate of magnesia, too, has been strongly recommended 

 for the purpose. Some experiments at Braidwood gave 

 the following comparative results : 



The crop without manure produced 125 stones per acre. 



,, with 3 cwts. of gypsum, produced 200 ,, 



,, with l^cwt. of sulph. magnesia, produced 290 ,, 



Thus half the quantity of sulphate of magnesia gave an 

 increase more than double that of the sulphate of lime. 



The mechanical treatment of the soil has been assigned 

 by some as the cause of failure ; and rolling, pressing, and 

 consolidation, by keeping sheep penned on the field, have 

 been recommended as the remedy. Mr. Berkeley, to whose 

 opinions we are obliged so frequently to refer, is inclined 

 to trace the cause of the disease to infection, from the 

 decaying vegetable matter of previous crops in the soil in 

 which it is grown. He says 1 "Now, as clover is usually 

 sown with barley after a crop of turnips, portions of which 

 are always buried with the plough, it is not impossible 

 that occasionally, though not always, the plant may be 

 impaired in constitution in an early stage of growth from 

 this cause, though the evil is not apparent in general, or 

 at least is not observed until the following year. We 

 have examined the roots 'of sick clover repeatedly, with- 

 out ever finding any unhealthy appearance about them, 

 or the slightest trace of any fungus spawn, which might 

 affect them. It is the part above the ground which is 

 the seat of the disease. The leaves lose their healthy 

 green, and ultimately the base of the stem, or what is 



1 Agri. Gaz., 1860, p. 10. 



