22 MIXED MANURES, CONSIDERED 



parts of chlorine and sodium ; but when dissolved in water a portion 

 of the water is decomposed, its hydrogen unites with the chlorine to 

 form muriatic acid, and its oxygen with the sodium to produce soda. 

 Hence salt in a dry state is chlorate of soda, and dissolved in water it 

 becomes muriate of soda. Its action in the soil depends on the effect 

 which the muriate of soda has on the carbonate of lime ; the latter, as 

 we have before observed, being found in almost all soils. By the 

 contact of these two salts, their acids and bases are interchanged, and 

 the compounds which are the result are carbonate of soda and muriate 

 of lime. Hence, as chalky soils abound more in carbonate of soda 

 than any others, salt is supposed to be most beneficial to them. Salt 

 applied in large quantities, it is well known, destroys plants ; and 

 hence it has been used in gardening, both in a dry and liquid state, to 

 kill weeds and worms in gravel-walks, which it does most effectually. 

 It has been used also for washing salads and other vegetables when 

 gathered for the kitchen, when they are supposed to contain snails, 

 worms, or insects. It forms a direct constituent of some marine plants, 

 and plants of saline marshes or steppes ; and, applied in small quantities, 

 it appears to hasten the decomposition of organized matter in the soil. 

 As a manure, however, it requires to be applied with very great caution ; 

 and, in gardens, is perhaps safest when used in walks for the purpose 

 of killing weeds and worms unless when given as a top dressing to 

 asparagus and seakale, or other plants that are found by the sea shore. 

 In suburban villas calcareous manures are often required for the 

 improvement of lawns and other grass lands ; and a stock of quicklime, 

 unslaked, should always be kept in a cask, or other closed vessel, to 

 be ready for use with water. Where lime is not at hand, common 

 potash or American pearlash dissolved in water, or urine especially 

 that of cows will have the same effect on insects as lime-water ; but 

 potash and pearlash are more expensive. 



Mixed Manures. 



Mixed Manures include coal ashes, vegetable ashes, street manure, 

 soot, and vegetable or vegeto-animal composts. 



Coal Ashes are of very different natures in different parts of the 

 country ; the constituents of coal varying in the quantity of clay and 

 lime, and. also of sulphur and iron, which it contains. Many persons 

 object entirely to coal ashes as a manure, considering them poisonous 

 rather than beneficial. The portions of coal which contain iron or 

 other metallic ores are converted by burning into hard porous masses, 

 which, when buried in the soil, absorb moisture, and consequently 

 soluble organic matter : and as the spongioles of the roots cannot be 

 supposed to penetrate into cinders or scoria3, that soluble matter must 

 remain there till it is washed out by rains or set free by the disinte- 

 gration of the cinder. Supposing this to be the case, the principal 

 benefit to be derived from coal ashes would appear to be that of 

 increasing the friability of stiff clayey soils. 



Vegetable Ashes are obtained by burning weeds, leaves, prunings, 

 or roots of woody plants, and in general all kinds of vegetable matter 



