114 



BOARD OF AGRICULTURE. 



regularly every week, which makes them happy and disposed to 

 begin the following one again. 



" It is thought that these beds will be important, not only for 

 American agriculture, but also for European, more particularly 

 for England. The phosphates can be sent over as ballast on the 

 cotton-ships, which formerly were obliged to bring their ballast 

 with them for their return voyage, since there was no ballast to 

 be found in the neighborhood of Charleston. No doubt the 

 material will be treated in various ways. One very simple 

 method is to roast the nodules over a fire of logs, (as some 

 varieties of iron ore are roasted,) and then to grind it to 

 powder ; or to apply the higher heat of an oven or lime-kiln ; 

 this leaves a mass which grinds up very easily. 



Comparative Analysis of Phosphates before and after heating. 



" It will be observed that the application has driven off the 

 water, organic matter, and the carbonic acid of the carbonate 

 of lime, setting the lime free. This has raised the other per- 

 centages accordingly. This process of heating would be com- 

 paratively cheap in a country where fuel is so abundant, the 

 pine-trees standing over the beds of phosphates. In this con- 

 dition it could be transported very easily, and ought to bring 

 fifteen dollars a ton, whicli would yield a handsome profit I 

 think. 



" The nodular phosphate has been treated with sulphuric acid 

 to form superphosphates. It is converted into such at a small 



