VII MANURES 6i 



and the leaves of trees and bushes. One of the chief importance 

 reasons of the value of a general manure is the fact that maSSre? 

 potash is an important constituent of it. When a potash 

 manure was required it used to be supplied as wood-ashes ; 

 but, in parts of Germany, large beds of potash salts, known 

 as kainit, have been discovered, and they have been dug 

 out and used as manure. Kainit contains salts of magne- Composition 

 sium and sodium besides those of potassium. In most parts ° ^'""* 

 of the West Indies, however, potash manures are unneces- 

 sary, as the potash can be obtained from the abundance of 

 refuse vegetable matters found everywhere. Ashes of plants, 

 decayed weeds, and green crop manures will supply all the 

 potash necessary for the growth of West Indian crops, 

 except in cases — as on some sugar-cane estates — where 

 the same crops have been raised for many years from the 

 same soil, and where vegetable manures are obtained with 

 difficulty. 



Common Salt is sometimes used as a manure, but it does 

 not come within any of the above four classes of special 

 manures. It is a compound of the two elements sodium 

 and chlorine, both of which are found in the ashes of plants. 

 It is always present in the atmosphere of maritime countries, 

 and it is carried down to the soil by the rains. It must not g^j^ ^^^ 

 be directly applied to tender plants as it would probably kill applied, 

 them, but to canes and cocoa-nut trees it may be sparingly 

 applied directly either as crude salt or as sea water. In 

 sugar cane lands, far away from the coast, it is stated that it 

 has been found advantageous to put some sea water into the 

 cane holes at the time of planting, and when cocoa-nut palms 

 are cultivated inland, and they do not thrive, an application 

 of salt or sea water has often been found to make them grow 

 vigorously and bear fruit. 



