On the Physical Properties of Soil. 



217 



Power 

 of con- 

 taining 

 liter 



KINDS OF EARTH. 



155 



Garden-Mould, abounding in vegetable matter, good for the 

 cultivation of Azaleas, Vacciniums, the Daphnes and Rhodo- 

 dendrons, and similar plants — 11 per cent, of lime, and 30 

 of volatile matter with clay and sand. 



179 



Black sterile Turf-Soil, containing much carbonized hu- 

 mus, and, in the whole, 76 per cent, of volatile matter. 



203 



Vegetable Soil, formed from decomposed leaves, and therefore 

 called leaf-soil ; employed for the artificial composition of vari- 

 ous garden-moulds — 33 per cent, volatile matter, with 16 of 

 fine lime ; the remainder being fine alumina and silica. 



210 



Wood-Soil, from decayed trees ; employed, like the leaf-soil, in 

 the formation of garden-moulds, in which various Cape and 

 New Holland shrubs are intended to be grown — 47 per cent, of 

 volatile matter, with 10 of fine lime ; the remainder being fine 

 clay and silica. 



366 



Very light Sterile brown Turf-Soil, from imperfectly de- 

 veloped turf, containing 89 per cent, of volatile parts. 



It results from this tabular view, that compound earths exhibit 

 still greater differences in their power of containing water than 

 could have been expected from the table of Gassicourt; the 

 soils employed in the climate of Germany for the cultivation 

 of corn appear to vary generally, in their power of containing 

 water, between 40 and 70 per cent. : when such power is consi- 

 derably greater or less, the soil is adapted much better for the 

 cultivation of certain plants, — namely : if less, for that of the 

 vineyards, and fir woods ; if greater, for meadows, or the cultiva- 

 tion of individual families of plants, of which several instances 

 are furnished by the preceding table: but there still remains 

 much on this point to be established by more extended observation ; 

 and it will only be after much experience and varied experiments, 

 that we shall be able to say with what power of containing water 

 this or that plant will with most certainty attain its perfect state ; 

 the mean quantity of rain and the mean temperature of a country 

 being necessarily of great influence on this point : in such 

 warm countries as have also a small mean quantity of rain, those 

 kinds of soil which have a great power of containing water 

 will, if other circumstances are the same, be the best; while 

 those soils which have, on the contrary, a small power of contain- 



VOL. I. Q 



