189 



waste, hair, horn, and leather it comes down to only 2 or 3, that 

 is to say : If an application of nitrogen under the form of nitrate 

 of soda, or the substances grouped with it, would produce a surplus 

 crop of l,0001bs. of fruit, an equivalent amount of nitrogen derived 

 from blood, bones, or meat would produce an increase of 7001bs., 

 and a similar dressing of nitrogen from wool waste, hair, ground 

 horn, or leather would only produce an increase of 200 to BOOlbs. 

 of fruit. It is thus seen how important in selecting the materials 

 from which nitrogen, phosphoric acid, and potash are to be derived 

 to see that the material is readily available. 



Phosphoric acid varies greatly in value, whether it is soluble or 

 insoluble in water. As regards " Citrate soluble " phosphoric acid 

 i.e., from a phosphate soluble in a weak acid solution, such as one of 

 ammonium citrate the value is intermediate between the above 

 two, thus : Water soluble phosphoric acid is worth in Western 

 Australia 7s. and in the Eastern States 6s. a unit. Phosphoric acid 

 insoluble in water is worth with us 3s. and in the East 2s. 6d. a 

 unit, whilst citrate soluble phosphoric acid, worth here 5s., is valued 

 in Sydney and Melbourne 4s. 6d. a unit. 



Potash in soluble salts is worth in Western Australia 7s. and 

 in the East 6s. a unit ; while potash in natural manures, such as 

 dried nightsoil, is worth 5s. and 4s. respectively. These prices, of 

 course, fluctuate a little according to the state of the market, the 

 quantity of fertilisers bought, and as to whether the transaction is 

 a cash one or one involving terms. 



To arrive at the value of a fertiliser, and unless it is specified 

 whether the nitrogen, the phosphoric acid, and the potash are derived 

 from the better prized material, these ingredients are considered as 

 being derived from the baser ones when calculating values. 



Knowing these values, it is easy, when furnished with^an 

 invoice certificate, to determine the real value of the manure offered. 

 Thus a mixed fertiliser contains 



Nitrogen (as Sulphate of Ammonia) ... 4 percent. 



Phosphoric Acid Water Sol 5 



Citrate Sol 2 



Insoluble ... ... ... 3 



Total Phosphoric Acid 10 



Potash or Muriate ... ... ... ... 4 



This statement is treated as follows : 



s. d. 



4 per cent. Nitrogen and Sulphate of Ammonia, 



at 16s 340 



5 per cent. Phosphoric Acid, soluble, at 7s. ... ] 15 



2 Citrate, sol., at 5s. ... 10 



3 Insol., at 3s 090 



4 Potash, at 7s 180 



^760 



