SOILS. ] 97 



J\agiiesian Character of these Soils. It is worthy of notice liere 

 that these soils are magnesian. This, I believe, in the future unf old- 

 ings of agricultural science, will be found to be a very important fact. 

 Magnesia has been a much abused substance. It was formerly sup- 

 posed that magnesian limestone made an inferior quick lime, and it 

 long lay under disfavor. But experience has finally shown that pre- 

 cisely the opposite is true. It is far superior to pure limestone for this 

 purpose. It was long, indeed almost even now, thought to be unsuited 

 for flux with iron ores, but this opinion has recently been modified. 

 Magnesian limestone, burned to quicklime, was formerly prohibited 

 as a fertilizer, and the ban has been only recently removed. That 

 some such revolution of opinion must take place in reference to its 

 utility as an ingredient of the soil seems to be forcibly suggested by 

 the following extracts from analyses taken from Prof. Johnson's ex- 

 cellent treatise " How Crops Grow," " being the average of all trust- 

 worthy analyses published up to August, 1865 ": 



MAGNESIA. LIME. 

 Per cent. Per cent. 



Wheat 12.2 3.1 



Rye 10.9 2.7 



Barley 8.3 2.5 



Oats 7.3 3.8 



Maize - 14.6 2.7 



Buckwheat 13.4 3.3 



Flax 13.2 8.4 



Beet 18.9 15,6 



Turnip 8.7 17.4 



CaiTot 6.7 38.8 



Peas 8.0 4.2 



Field beans 6.7 5.2 



Garden beans 7.5 7.7 



Clover seed 12.2 6.2 



Potatoes 4.5 2.3 



From which we see that in the grains, the magnesia predominates 

 decidedly. In the fibrous part of the plant the opposite is true; as 



follows : 



MAGNESIA. LIME. 

 Per cent. Per cent. 



Winter wheat straw 2.6 6.2 



Bye 3.1 7.7 



Barley 2.4 7.6 



Oats 4.0 8.2 



Maize 5.5 10.5 



Peas 7.7 37.9 



Field beans -7.8 23. 1 



Garden beans 5.2 27.4 



Buckwheat 3.6 18.4 



