240 MANURES FOR TREES 



position of many special manures. It contains in 

 100 parts : — 



Sulphate of magnesia assists in the formation of 

 starch, in the development of chlorophyll, and it 

 enhances the colour and vitality of leaves. Sir 

 John B. Lawes used it in his mixed manures 

 for oats, and Ville states that it is an essential 

 for plant-life. It is present in kainit and other 

 manures. 



It is largely used in the special manures for 

 French vines ; and the American vine flourishes 

 best in those soils containing a high percentage of 

 magnesia. The immortal chemist, Liebig, recom- 

 mended magnesium sulphate for the growth of 

 plants generally. 



Sodium Sulphate is a valuable manure of 

 certain plants — leguminous plants and trees in 

 particular. It answers best on light soils. 



Silica is a constituent of the ashes of all plants, 

 and is present in all soils. Ville proved that " the 

 omission of soluble silica is very prejudicial to 

 vegetable activity." He recommended soluble 

 silicates for the growth of plants ; and Dr. E. 

 Wolff proved that the absorption of soluble silicic 



