CARBONATE OF LIME. 1385 
and Germany. Our own iron ores, being poorer in 
phosphorus, do not make much of this substance. 
It is in great use in the Old World. Germany alone 
uses 2,000,000 tons of it each year. Wherever tested 
in America it seems to give very satisfactory re- 
sults. The writer tested it on Woodland Farm many 
years ago and never got stronger, healthier alfalfa 
than by its use. 
Basic slag usually contains from 16 to 20 per cent. 
of phosphoric acid with from 36 to 50 per cent. of 
lime. It is said that the phosphoric acid is in 
a form that is nearly all available, and it can- 
not revert in the soil nor leach away. There is 
hardly a farm east of the Missouri river where 
more phosphorus will not yield profit. Where 
freights are not too high, basic slag costs no more 
for the available phosphoric acid than any other 
source of phosphorus, and thus the lime is gotten 
free. It is advised that from 1,200 to 1,500 pounds 
per acre of basic slag be applied where alfalfa is 
sown. The large surplus of phosphorus thus given 
will not leach away, but will remain to feed the 
plants for some years, while the lime will help 
sweeten the soil. 
Basic slag costs too much for use at present in the 
cornbelt states. Where it is available is in New 
England, New York, and along the Atlantic sea- 
board. The price is about one dollar per unit of 
phosphoric acid; that is, slag analyzing 17 per cent. 
available phosphoric acid would cost the consumer 
about $17 per ton. At present writing the Coe- 
