MANURES. 29 



trees. There are many reasons for my decision. In 

 the first place, too much digging round an established 

 tree is sure to result in damage to the roots ; in the 

 second place, at no time should strong or fresh 

 manure be brought in contact with the roots ; in the 

 third place, as a top dressing it forms a frequent 

 mulch, which the earth receives by degrees. Remem- 

 ber, soil, like plants, can be overfed at any one time, 

 ^although, given time, it can store up the substances 

 administered. Let us turn to nature and take a 

 lesson from her; she both top dresses and digs in. 

 Top dresses in the autumn with leaves and decayed 

 vegetation, which all through the winter months is 

 gradually returned to the soil, washed in by rains 

 and dug in by worms. See the burial beetle place 

 beneath the soil a dead bird or small animal ; see 

 insects burrow into soil and leave in it store of sur- 

 face matter that must decompose and fertilise. 



The leaves of a giant tree, if left where they fall, 

 are soon returned to the earth, especially in a wet 

 'winter. If you examine the surface of the ground 

 you will notice how the worms drag them beneath the 

 soil, doubtless with the intention of keeping the holes 

 open to allow the rains to run down the ptpes they 

 make, and air to be drawn into the soil. 



Water and carbon form the greatest part of a 

 plant's content, and while the elements feed the leaves 

 and branches above, the worms administer to the 

 roots below, drawing down the air as surely as a 

 plunger in a pump, and conveying the water to the 

 roots in quantity by the holes or drain pipes that they 

 have made. 



Roses, like most plants, require but little of the 

 salts of the earth ; carbon and water form their prin- 

 cipal necessities. 



If you would prove this, do what Van Helmont, 

 a celebrated alchemist, did in the early 17th century . 

 Grow a tree in a large pot, weigh the soil, pot and 

 tree at planting, and then in three c5'r four years weigh 



