:ilAP. V] THE SOIL 97 



The observations were carried on in tiie forest of Champfetu near Sens, where, 

 n a small area, calcareous soil (chalk) and silicious soil (sand and sandy clay) 

 Iternatc, because the clay and sand overlie the chalk, as tertiary strata, forming 

 ometinics a thick deposit and sometimes a thin one, or have been completely 

 .■ashed away. The area in question had been planted with different species 

 f forest trees, such as Pinus sj'lvestris, P. Laricio, larch, silver-fir, spruce, oak, birch, 

 .liich had for the most part thriven equally well on each of the strata : whereas the 

 laritime pines and sweet-chestnut trees that had also been planted grew luxuriantly 

 n the soil that was poor in lime, but remained stunted on the calcareous soil and 

 3on died ; and so much the sooner, the thinner the upper stratum poor in lime, 

 ^'hercver the sandy soil poor in lime was absent, both trees could scarcely live 

 : all. 



The chestnut trees and maritime pines on the calcareous soil differed from those 

 n the sandy soil, not onlj' by their stunted growth and bj' the abundance of their 

 ead twigs, but also by the smaller size and the yellower colour of their leaves, which 

 the case of the chestnut were partly white. Thus on silicious soil the pine needles 

 ereo-i75-o-iS9 m. long and 2 mm. broad, whilst on calcareous soil the length of the 

 eedles was between 0092 and o-lll m. and their breadth 1-5 mm. The chestnut 

 aves on clay and sandy soil were up to 0-253 ni- long and 0-072 m. broad, but [on 

 ilcareous soil at the most 0-149 '"• long and 0-056 m. broad ; those at the end of the 

 ■ig were much smaller, often degenerate and nearly white. 



The analysis of the soils from which the specimens of Pinus Pinaster had been 

 ken, the composition of whose ashes will be given below, gave the following 

 suits : — 



NALYSIS OF SOILS IN THE FOREST OF CHAMPFETU UPON WHICH 

 PINUS PINASTER GREW (after Fliche and Grandeau). 



Silicious clay soil. C.ilcareous soil. 



Surface soil. Subsoil. Surface soil. Subsoil. 



Water 1-75 1-66 2-90 2-46 



Organic matter .... 5-50 2-t)4 6-53 5-39 



Lime 0-35 0-20 3-25 24-04 



Magnesia 0-38 0-47 0-47 1-31 



Potash 0-07 0-03 0-04 o-i6 



Soda ...... o-o6 0-04 0-03 0-07 



Phosphoric acid . . . 0-64 0-42 0-29 o-i8 



Residue (silica, clay, ferric oxidel 90-55 92-70 83-00 46-80 



Carbon dioxide . . . 0-70 1-64 3-54 19-59 



100 100 100 100 



In the analysis of the ash of the maritime pine grown on these soils, about equal 

 iumes of wood, bark, and leaves were used. For the purpose of comparison, Pinus 



ricio, which prefers a lime-containing substratum, was taken from the calcareous soil 

 J analysed. 



IIMPER H 



