



OF EXPERIMENTS WITH LI MM. 243 



occasional application of such a lime by itself, will be likely to 

 promote in a greater degree the productiveness of the soil. 



3. In like manner, should it be proved by experiments, such as 

 have been suggested in the previous sections, that limes which 

 contain a proportion of silicate are specially useful for certain 

 soils and crops, it will then become a matter for consideration, in 

 localities where the most accessible limes are of a very pure 

 character, whether an importation of less pure lime may not 

 occasionally be profitable, or whether, during the process of 

 burning in the kiln, siliceous sand may not be advantageously 

 added to it. 



The natural presence of gypsum in a soil, or of phosphate of 

 lime in considerable quantity, will also materially interfere with 

 the results of many of those experiments I have recommended ; 

 their possible influence, therefore, ought in all cases to be taken 

 carefully into account. 



4. Suggestions for experiments on over-limed land. 



Land to which lime has been applied too frequently, or in 

 too large doses, is not only liable to exhaustion, but to be ren- 

 dered so light, open, and spungy, as to sink under the foot if 

 of a fenny or peaty character, to become powdery and liable to 

 be drifted by the wind and though it may still grow turnips 

 and barley, to be unfit to yield profitable crops of sown grasses 

 and oats. 



The term overtimedis given to such land, a designation which 

 seems to imply that in the soil lime really exists in too great 

 abundance. Analysis, however, has satisfied me that such is 

 not the case, and that the evil is a mechanical or physical, and 

 not a chemical one.* 



When this evil presents itself, therefore, I would suggest, 

 along with bountiful treatment to restore it if exhausted by 

 previous cropping the trial of one or more of the following 

 methods of solidifying it : 



1. Laying down to grass, and keeping some years in pasture. 



2. Eating off turnips with sheep. 



* See Contributions to ticientijic Agriculture, p. 24 ; or Use of Lime in Agricul- 

 ture, p. 121. 



