No. 144. J ■ 427 



This small scaly insect secretes itself beneath a woolly scale or 

 cocoon, and adheres so firmly to trees, as to be scarcely capable 

 of dislodgment. A single Insect in a few weeks covers trunk and 

 branches with an innumerable multitude. If anything will de- 

 stroy this pertinacious and destructive pest, it will prove a great 

 blessing to fruit growers. 



Prof. Mapes says, that carbonate of soda wash will effectually 

 put an end to their depredations. 



(The subject of animal charcoal having been mentioned, Prof. 

 Mapes said, he had used two tons of sugar refiners' refuse bone 

 black, on a quarter of an acre, without perceptible benefit on ac- 

 count of the insoluble phosphate composing it in great part; but 

 400 lbs. of superphosphate made soluble by sulphuric acid, fitted 

 an acre for a good crop.) 



Mr. Field said, that one word mentioned by Prof. Mapes, com- 

 prised the whole secret of vegetation — solubility. If it were pos- 

 sible to make the farmer once comprehend this requisite of the 

 growth of plants, the lost kalon, the great mjstery of vegetable 

 sustenance, would be discovered; plants cannot take up solid par- 

 ticles, however small. Animal charcoal is principally composed 

 of the simple phosphate of lime, which is too slowly decomposed, 

 to yield its phosphoric acid in solution, though the latter is an 

 important agent in vegetation. The phosphate must become super- 

 phosphate, to yield its nutritive powers readily by solution. Wheat 

 refuses to stand erect, and ultimately to perfect itself upon some 

 sandy soils, although it needs precisely their principal component, 

 silex — simply because that silex is not soluble. 



No man can make his field fruitful, by merely adding sand for 

 the silicious material of plants, nor insoluble phosphate, to yield 

 the indispensable phosphoric acid. Nor will feldspar thrown 

 upon a soil, robbed for years of potash, restore it to fruitfulness, 

 although composed largely of that salt. But pho:=phates, sand 

 and by chemical change, give up in solution their respective salts, 

 and soils abounding in their insoluble compounds, may be forever 

 barren. 



