69 



could perceive no difference ; but beyond this, in pro- 

 portion to the quantity of manure, so did the plants 

 decline and turn white. He tried plants in composts 

 of charcoal and manure, and of charcoal, earth (cal- 

 careous,) and guano, but without success ; nothing 

 seeming to suit them here but their favourite red soil. 

 Mr. Solly examined this soil, and says it is free from 

 stones ; and though it appears to consist in great part 

 of a coarse ferruginous sand, on examination is found 

 to contain no sand, being easily rubbed to an impalpa- 

 ble powder in a mortar, and showing no grittiness 

 under the pestle. A portion of the soil, freed from 

 the larger fragments of wood, roots, and bark, which 

 it contained, gave an analysis of the following com- 

 position, in ten thousand parts : — 



Silica .. .. 3090 



Alumina . . . . . . 2400 



Oxide of iron .. 1832 



Lime (chiefly as carbonate) . . 132 



Magnesia . . . . . . 8 



Potash in a soluble state . . 5 



Potash combined with earthy l ^ 



matter . . . . J 



Phosphate of iron . . . . 9 



Sulphuric acid . . . 2 



Chlorine . . . . . 4 



Ammonia . . . . a trace 



Organic matter . . . . 990 



Water .. .. .. 1508 



10,000 



