ON COMMON DUNG BEDS. 31 



moist, and the thermometer has indicated only 

 a proper heat ; but it must be borne in mind, 

 that it is not the quantity of heat that injures 

 the plants, but the quality. It is a general, but 

 mistaken impression, that if a bed appears dry 

 and white near the surface, it is attributable to 

 too great a bottom heat ; but such is not always 

 the case, for it often happens that the destruc- 

 tive heat is contained within a few inches of the 

 top of the bed ; and, consequently, that it may 

 generally be corrected by removing the dung on 

 the immediate surface, till you come to where it 

 is dry and looking mouldy. When this is the 

 case, fork the dry mouldy part over, and give it 

 as much water as will make it moderately moist ; 

 then return the dung removed from the surface 

 to its proper place. When the whole of the 

 surface has been dealt with in this manner, add 

 to the tops of the linings, with a view of coun- 

 teracting any injurious effects that may arise to 

 the plants from the watering which the bed has 

 been subjected to. A little additional covering 



