i,4ii- The percentage composition of the sample of 

 superphosphate of lime analysed was : 

 Moisture =16-46% 



41 Organic matter &c."= 9*51 ,, 

 Sand = 6-45 



CaH 4 P 2 O* =20-03 (=26-6 % of "soluble phosphate") 



Ca 3 P 2 O 8 = 3'49f 



CaSO 4 =43'o,, 



Alkalis &c. = -96 



lOO'OO 



CHAPTER CXXXVII. 



ANALYSIS OF NITRATE OP SODA AND SAI/TPETRE. 



: 



TN analysing a sample of Nitrate of Soda, or of Nitrate 



of Potash, the method employed is to find out the tm* 



purities and to estimate the amount of pure Nitrate of 



Soda, or Potash by difference, These impurities are gene* 



rally (i) Moisture, (2) Sand and other insoluble mattery 



(3) Sodium and chloride (4) Sodium or Calcium sul^ 



phate. 



1 A I 3^ 35 grammes of a sample of Sodium Nitrate or 

 Potassium Nitrate should be weighed out, and put in a clean 

 beaker, and dissolved in about 300 c. c. of distilled water. * A 

 Swedish paper is at the same time put inside a tube and left in 

 the water-oven to dry. Next day, the tube is stoppered and 

 put aside to cool, weighed after an hour, and weighed again 



