5i© SCIENCE PROGRESS 



Conifers are afterwards planted among it. And on poor, dry, 

 limy soil thrown out of cultivation near Jena over thirty years 

 ago, good coppices of White Alder have been raised, in which 

 other trees, and chiefly Ash, Maple, and Sycamore, have begun 

 to sow themselves spontaneously. The intermingling of White 

 Alder along with Spruce (about one row in every six) on poor 

 limy soil, or of sowing clover and other papilionaceous plants 

 thriving on lime, effects a marked improvement on the growth 

 of Spruce ; while on sandy soil equally beneficial results are 

 obtained by sowing perennial lupine. How such methods of 

 improving the productivity of poor soil converted into wood- 

 land, and how far Continental experience has shown that 

 artificial fertilisation of poor soil can be advantageously carried 

 out by the addition of chemical manures, may perhaps form 

 the subject of a subsequent article. 



