Phosphates 



slag may cause a serious irritation to the eyes. 

 He should be provided with motor goggles, if 

 necessary. 



When the slag has caked in hard clods because 

 of careless storage it must first be finely pounded 

 with a heavy hammer. The lumps must not be 

 thrown on the land as they are. 



The sacks of slag should never be stood on the 

 ground in the storing place, but placed on a plank 

 platform. 



Slag is adulterated with many things, of which 

 some are inactive — such as ground cinders, or the 

 waste from coal mines, and others having very little 

 action — such as mineral phosphates. 



The numerous trials which have been carried 

 out in the countries where basic slag is largely used 

 have demonstrated its excellence, and its great 

 value as a manure. 



Basic Superphosphate. 



Basic superphosphate is simply superphosphate 

 to which basic slag has been added. Since, however, 

 we can obtain both constituents separately when it 

 is desirable to use them, basic superphosphate has 

 the usual drawback of compound manures — the unit 

 is too dear. 



It has been argued that monocalcic phosphate is 

 transformed into bicalcic in this mixture. As we 

 have already had occasion to say, apropos of reverted 

 phosphates, this in our eyes is not a great incon- 

 venience, as long as the manure is not given as a top 

 dressing but is harrowed in. As a matter of fact, 

 when the soluble phosphate of the siiperphosphate 



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