PRINCIPLES OF GARDENING. 51 



ted ; and we thus return to the soil the mineral constituents which 

 the plants have taken away, and the earth regains that which has 

 been lost. 



We have employed the ashes of the burnt cuttings of trees over 

 our vine borders with good success : we have also used dissolved 

 bones for the same purpose* We have used ivory dust in large quan- 

 tities, beneficially. But care must be taken in buying bones, as I 

 once had some which killed every root which touched them, and 

 which had probably been mixed with noxious chemicals. Lime, 

 chalk, and brick rubbish have ever been found useful ingredients ; 

 and brick rubbish is one of the most valuable materials which can 

 be used, — as the delicate Alpine plant, the rapid-growing vine, and 

 the largest fruit-tree all delight to grow in it. 



Nitrogenized matter must also be added to the soil. My garden 

 is naturally so poor that it will not return the seed sown, without 

 manure containing nitrogenized matter. Nitrogen, to a small extent 

 may be obtained from the air ; though, unquestionably, the plant 

 derives the greater part, if not the entire amount of its nitrogen from 

 the soil. It may be derived from ammonia, a compound of nitrogen 

 and hydrogen, and its salts; it may be derived from nitrates, com- 

 pounds of nitrogen and oxygen ; and lastly, it may be obtained by 

 the direct absorption of nitrogenized animal or vegetable matter. 



Vegetals are competent to take nitrogen directly from decom- 

 posing animal matter, which may be known by watering them with a 

 solution of putrid matter. I have known asparagus to be so watered, 

 but nothing could be more offensive than the. vegetal when placed 

 on the table. The cabbage tribe, which are gross feeders, are also 

 offensive, and perhaps sometimes dangerous after having been so 

 treated. For this reason at my garden all putrid manures are strictly 

 forbidden ; and stable dung, in an ammoniacal state, exclusively used. 

 This is the best manure for a garden, and yields the finest flavoured 

 vegetals. As of necessity our garden is compelled to yield large 

 produce, so it is requisite to supply the ground with large quantities,- 



of manure. 



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