AGRICULTURE WITH CHEMISTRY. I77 



Clay is the fittest substance to be applied with a view to 



alter the arrangement of the parts of a chalky soil. Peat 



is a good application to soils of this nature, which are 



frequently termed hungry soils, and very deficient in ve- 



getable matter. And as a sufficiency of dung is not -to he 



procured to manure fully every part of a farm, peat 



may be applied in one or other of the states of prepa- 



ration already mentioned. Unfortunately for the improve- 



ment of chalky soils, neither clay nor peat is to be found 



but at the extremities or outskirts of the extensive tra6t$ 



of chalky countries : wherever they are to be had, the , 



r 

 application of them should not be negle&ed. Calcareous 



soils, which have long been under the plough, contain a 

 large proportion of phosphat and oxalat of lime. These 

 insoluble saline matters may be rendered serviceable to 

 vegetation by alkalis, vitriolic acid, vitriolic neutral salts> 

 (especially if superacidulated) and by pyrituous and 

 aluminous substances. Even green vitriol, which has hi- 

 therto been considered as unfriendly to vegetation, will, 

 when in a proper manner applied to soils like this, con- 

 siderably improve and promote the growth, of pasture 

 grasses. 



It 



