118 SELECHNG, PLANTING, AND CULTIVATION. 



of trees hitherto barren. It should be understood, 

 that a tree can no more grow, and produce fruit, 

 when one of Us elements is lacMng^ though all the 

 others are present, than a house can be built, when 

 all its materials, except the nails, have been obtained. 



Mr. DoA\^^iNG was of the opinion, that bones finely 

 ground and mixed with wood- ashes, would prevent 

 the leaf-rust ; and several nurserjmien who have used 

 the comj)ost seem to adopt the same belief. 



Mr. Bahky very tersely and happily remarks : 

 "Bone-dust, blacksmiths' cinders, muck-lime, wood- 

 ashes, and half a dozen otlier things, have been recom- 

 mended to be compounded, in pecks and half-pecks, 

 all with a view to remedy the rust, or leaf-blight, that 

 no man can say originates in any defect of the soil." 

 But the failure of specific manures to produce certain 

 results, for which no rationale founded in natural 

 science could be given, ought not to deter us from 

 investigation in a philosophical manner. Some simple 

 facts illustrative of the value of scientific knowledge 

 in the management of the Pear may be stated. *0n 

 a plot of rich ground, where blight had year after 

 year affected the Pear, its farther ravages were pre- 

 vented by a large application of lime ; this was 

 accounted for by the destructive action of the lime 

 upon the excessive organic matter of the soil, thus 

 inducing a more stocky and well ripened growth. 

 Dr. ]Sr. P. Teft, of Onondaga, so changed the appear- 

 ance, in shape and size, of the fruit borne on a Yir- 

 galieu pear tree by a very large application of leached 

 ashes, that specimens of it received the premium from 

 the American Institute as the best new table-pear. 



