CHAP, ii.] APPLICATION. 33 



become soured by stagnant water. It is also 

 frequently applied to grass; but, when this is 

 the case, it generally sinks through the soil 

 without mixing with it, so as to form a distinct 

 stratum two or three inches below the surface. 

 This may be seen in several places, where grass 

 fields have been cut through to form railways ; 

 particularly on the Midland Counties Railroad 

 near Leicester, where the white, line formed a 

 little below the surface by the lime is verv con- 

 spicuous, from the deep red of the sandstone 

 which forms the subsoil. Quicklime, when it 

 is laid on land, and allowed to remain within 

 the influence of the air, absorbs carbonic acid 

 gas from the atmosphere, and thus becomes of 

 great service to plants in supplying them with 

 carbon. 



Nitrate o£ soda is a mineral which has been 

 lately extensively introduced from South Ame- 

 rica, where it is found in a natural state in great 

 abundance. It is a powerful manure, abound- 

 ing in nitrogen, but its action is very uncertain. 

 W here it has its proper effect, its presence 

 may be traced by the richness of vegetation 

 which it produces, and by the dark green which 

 it gives to the leaves ; but it does not appear 

 to act favourably in the production of seeds, 

 fruit, or grain. Nitrate of potassa, or saltpetre, 

 is more certain, though less powerful, in its 

 effects. 



The following is a Summary of the Rules to 

 be observed in applying Manure to Gardens. — 

 To remember that the best and safest manure 

 for all soils is rotten horse-dung, such as the 

 remains of an old hotbed, when it is wished to 



D 



