COMPOSITION OF VARIOUS TREES 155 



The ashes of this tree contain in 100 parts : — 



One ton of Populus extracts 26 lbs. of mineral 

 matter from the soil. 



These trees are useful for forming screens in 

 town or suburban gardens. They grow well in 

 the suburbs of Manchester, where the soil is a 

 moist clay. 



The wood is used for carving, charcoal, &c., and 

 the bark is used for tanning. The bark of Populus 

 tremula and other species contains salicin and 

 populin (benzoyl-salicin). 



Red-Flowering Currant {Ribes sanguineum, 

 Natural Order, Saxifi-agacese) is a hardy flowering 

 shrub with deciduous leaves. It grows in ordinary, 

 soils, in a sunny position. 



