224 



On Superphosphate of Lime. 



some similar material. Samples Nos. 7, 8, 9, owe their inferiority 

 in great measure to the parsimonious use of the acid ; but, in addi- 

 tion to this, they must either have been made from a material con- 

 taining much carbonate, or gypsum must have been added to 

 them. In No. 6 this latter fraud must undoubtedly have been 

 practised : it is a mixture of a very small quantity of real super- 

 phosphate with sulphate of lime — the whole quantity of phosphate 

 in any shape not reaching 3 per cent. 



The following analyses show what an average sample may 

 fairly be expected to reach. I by no means allow that they are so 

 good as they ought to be, because it is easy to show that they can 

 be made better at the present prices and with a fair remuneration 

 to the maker. 



Analyses of Superphosphate of Lime (Average Samples). 





No. 10. 



No. 11. 



No. 12. No. 13. 



No. 14. 















Organic matter and salts of am- 



Bi-phospbate of lime (soluble) , 

 Neutral pbospbate (insoluble) , 



Hydrated sulpbate of lime (gyp- 

 Alkaline sulpbates, muriates, 

 and substances undetermined 



10-45 



10-00 

 12-40 

 9-79 

 7-52 



1 49-84 



22- 57 



23- 99 

 10-78 



3-70 

 10-16 



j 17-68 



i 11-12 



5-94 



15-54 

 10-38 

 8-15 

 2-99 



1 57-00 



18-00 



18-11 



8-32 

 14-76 

 331 



37-50 



21-41 



10-90 

 8-09 



13-31 

 7-21 



39-08 



100-00 



100-00 



100-00 



100-00 



100-00 











Neutral pbospbate to wbicb tbe 

 bi-pbospbate is equal . 



0-68 



18-23 



1-61 

 15-85 



1-16 

 15-31 



1-23 

 12-27 



0-88 

 11-91 



My experience leads me to believe that the farmer in buying 

 superphosphate of lime has a right to expect that it shall contain 

 at the least from 8 to 11 per cent, of bi-phosphate, which is 

 equivalent to from 12 to 15 per cent, of the neutral phosphate, 

 rendered soluble. He has a right also to expect that it should 

 contain from ^ to 1^ per cent, of nitrogen, which is an indication 

 of so much animal matter or ammoniacal salts being present, unless, 

 indeed, he purchases a mineral superphosphate^ knowing it to be 

 such. Agricultural experience seems *it the present time to lean 

 to a judicious mixture of soluble phosphate with animal matters 

 in preference to a purely mineral manure ; but it must be re- 

 membered that this is not indispensable in cases where the land 

 is in good condition, or where farm-yard manure is largely applied 

 for the turnip crop : in these cases superphosphate is applied 



