66 THE CULTIVATION OF THE 



for use by cultivation, and changed to the peroxide, the 

 form in which it is available for plant-food. The color 

 of all soils is, probably, produced by iron, and, of course, 

 nearly all soils contain it, and tillage renders it available. 

 Still, if my orchard did not thrive I would use some iron 

 about the trees in a metallic state. Get the scrapings of 

 a blacksmith-shop, especially where horses are shod, 

 and thus get the hoof-parings, etc., and iron-scales. 

 Also iron-scales from rolling-mills, etc. A salt of iron 

 in a fertilizer with phosphoric acid, etc., would be expen- 

 sive and of doubtful propriety, as it might cause the 

 reversion of the phosphoric acid to its insoluble state as 

 phosphate of iron and alumina, which exists in crude 

 phosphate. The scales of rolling-mills, blacksmiths' 

 forges, etc.. are generally the magnetic oxide of iron, 

 and they get a little oxygen from the air and from 

 moisture. Subject them to damp earth, etc., by putting 

 them around the tree, and they change to the hydrated 

 peroxide of iron, the form of iron available as plant-food. 

 The chemist, I believe, would tell you that they change 

 from FE3O4 to FEgOg-FHaO. 



Pruning may act directly as a fertilizer. When the 

 trees languish, and especially if old, cut out the middles 

 well, and cut back the new wood one-half, or top them 

 altogether, and let a new top come out with strong help 

 from fertilizers. In some places old orchards are doing 

 well and new orchards prematuring. It is my advice to 



