ON THE CHEMICAL CONSTITUENTS OF SOILS. 225 



Resinous matters .... 2-040 



Coal of humus and water . . . 32- 100 



100000 



The next analysis represents the soil after being 

 burnt. 100 parts by weight of the soil left after 

 ignition only 50 parts. 100 parts of these ashes 

 consisted of: — 



Silica and siliceous sand . . , 95*204 



Alumina ..... 1*640 



Peroxide of iron .... 1 -344 



Peroxide of manganese .... 0*080 



Lime in combination with sulphuric acid . 0*544 



Magnesia combined with silica . . 0*465 



Potash and soda .... 0052 



Phosphoric acid (principally as phosphate of iron) 0*330 



Sulphuric acid .... 0322 



Chlorine ..... 0019 



100-000 

 By comparing this analysis with the one which 

 has preceded it, an increase in certain of the con- 

 stituents is observed, particularly with respect to 

 the sulphuric acid, potash, soda, magnesia, oxide of 

 iron, oxide of manganese, and alumina. From this 

 it follows, that the humus, or in other words, the 

 vegetable remains, must have contained a quantity 

 of these substances confined within it, in such a 

 manner that they were not exhibited by analysis. 



Oats and barley were sown on this land the 

 second year after being reclaimed, and both suffered 

 much from rust, although different parts of the soil 

 were manured with marl, lime, and peat-ashes; whilst 

 other portions were left without manure. In the 

 first year, all the different parts of the field pro- 

 duced potatoes, but they succeeded best in those 

 divisions which had been manured with peat-ashes, 

 lime and marl. In the second year, oats mixed with 

 a little barley were sown upon the soil; and the 

 straw was found to be strongest on the parts treated 

 with peat-ashes, lime, marl, and ashes of wood. Red 

 clover was sown on the third year ; it appeared in 

 best condition on those portions of the soil manured 

 with marl and lime. Upon the divisions of the field 



