34 GARDENING FOE TUB SOUTH. 



Caustic potash acts upon decaying matters like lime. As 

 a manure, it is always used in the form of a salt, generally 

 as a carbonate, but also as a chloride and a nitrate. As 

 a carbonate, it is found in wood ashes, which are every- 

 where considered as a most valuable manure, and which 

 add great efficacy to all composts to which they are ap- 

 plied. The abundant potash from burning the brush and 

 timber is one cause of the great fertility of freshly cleared 

 lands. Chloride of potassium exists in soapboilers' refuse, 

 which is a good manure, chiefly from the presence of this 

 salt therein. Nitrate of potash (saltpetre) is the most 

 useful of the salts of potash, promoting the vigor of plants 

 and rendering their tissues solid. Potash, like lime, should 

 not be combined with animal manures, but in composts 

 of vegetable refuse will be found very useful, particularly 

 as an application to vines and fruit trees. Upon turnips, 

 cabbages, and other members of the cabbage tribe, it has, 

 when applied in the form of soapsuds, an immediate good 

 effect. (Zrindley.) 



Soapsuds is also most excellent as a manure for roses. 

 Potash has the same effect as lime upon the texture of 

 soils, in rendering adhesive ones more friable, and light 

 ones more adhesive. Soils, in cultivation, if not manured, 

 soon part with so much of their soluble potash, that rest 

 and fallowing are required to render available that which 

 exists naturally in all clayey soils, but not in a soluble 

 form to the extent required by growing plants. After 

 ammonia and phosphoric acid, potash is the most likely to 

 be of benefit to the soil. 



Soda is present in the structure of plants, but in smaller 

 quantities than potash, for which it is regarded by Liebig 

 as a natural equivalent. Some plants which naturally 

 grow in a soil containing a salt of soda will grow equally 

 well if a salt of potash is present, while, if both are ab- 

 sent from the soil, they will not thrive. Hence if a soil 

 contain enough alkaline matter for many plants, it does 



