116 
The vicia faba contains no free alkali, and not one per 
cent, of phosphates; lucerne, only 0.83 per cent, of phos- 
phates of lime. 
10,000 parts of wheat straw contain 47.3 phosp. lime. 
Ditto ditto grain 79,45 ditto. 
I have subjoined a table of the constituents of the ashes 
of plants found in most of the cultivated plants.* In another 
column are the quantities of gluten or albumen, and therefore 
the proportional quantity of nitrogen. In the other table of 
the analysis of manures, it will be seen that the dung of 
animals contains principally neutral salts and phosphates, 
and, therefore, can afford only inorganic substances to plants. 
They contain very little nitrogen; that of the cow 1 in 
200,000 parts, that of the horse one per cent. The ashes 
of trees contain various saline and earthy constituents, and 
are used in Flanders ; the ashes of the beech 20 per cent, of 
phosphates. 
Bones contain 55 per cent, of phosphates of lime and mag- 
nesia, and 8 lbs. of bones contain as much phosphate of lime 
as 1000 lbs. of hay or wheat straw, and 2 lbs. of bones as 
much as 1000 grains of wheat or oats. 
Therefore 40 lbs. of bone dust, says Liebig, per acre, is 
sufficient to supply three crops of wheat, clover, potatoes, 
and turnips, with a sufficient quantity of phosphates. 
The urinous liquids abound in phosphates and neutral 
salts. 
Peat ashes contain silicate of potash and some phosphates, 
and might therefore replace the dung of the cow and horse, 
when they can be obtained. 
III. I now proceed to describe the state of agriculture, as 
at present existing over these different soils, and to offer sug- 
gestions for their improvement. 
The Magnesian Limestone soils are strictly calcareous, 
* See Table II. at the end. 
