300 Journal of Agriculture, Victoria. [10 May, 1917. 



Twenty shillings spent in the purchase of Dried Blood in 1917 will 



only have the purchasing power that Ifis. had in 1912. In other woidSt 

 nitrogen purchased as dried blood in 1912 tor 20s. would cost the sum 

 ot approximately Z5s. in 1917. 



Bone Dust. 



The central diagram on Graph II. relates to the purchase of Bone 

 dust. Attention is drawn to the fact that the computations are based 

 on the main list of registered brands. This procedure was necessary for 

 the sake of comparison in that the 1916-17 supplementary registrations 

 are not available. 



Bone dust is, or should be, the product obtained by grinding or 

 disintegrating bones or recent animal matter. This fertilizer is the 

 product of local industry. 



Small parcels were obtained from other States, viz.. New South 

 Wales and Queensland, in bygone years; but, as a matter of fact, a fair 

 amount of bone dust in the adulterated condition, i.e., " bone fertilizer," 

 annually finds its way out of Victoria. 



The process of manufacture is simplicity in itself. The bones are in 

 thp first place subjected to steam pressure in a diges.t€r for the dual 

 purpose of extracting the tallow and softening the bones. The latter 

 are then discharged from the digester and ground in a mill or dis- 

 integrator, of which there are several kinds in use. 



The bone dust diagram previously referred to shows the price of 

 bone dust to be fairly constanti during the period under review. How- 

 ever, computing from 1907 over a period of ten years, we find that bone 

 dust has increased in price. In 1907 84 lbs. cf phosphoric acid, to- 

 gether with 13.5 lbs. of nitrogen, were received for every 20s:. expended 

 in the purchase of bone dust, whereas in 1917 for the same monetary 

 consideration only 71 lbs. of phosphoric acid and 12 lbs. of nitrogen are 

 obtained. 



Roughly, this increass in price is 15 per cent. 



Bone FtRTiLizER. 



The term " bone fertilizer " is strictly Victorian. The manure is a 

 mixture of bone dust with either rock phosphate, gypsum, marl, super- 

 phosphate, or any such material. 



Some brands may contain a proportion of each of the foregoing 

 materials, and in many inst^inces the proportion of bone dust is so small 

 as to be hardly discernible. 



The diagram on the left of Graph II. shows the amounts of phos- 

 phoric acid and nitrogen received in exchange for 20s. in the purchase 

 of bone fertilizer during the past six years. 



The graph explains itself, but it is interesting to note the decline in 

 the amount of phosphoric acid in tlie years subsequent to 1912, and 

 the decline in the pounds of nitrogen received in 1917. 



The increase in the price of bone fertilizer over the period 1912-17 

 is approximately 10 per cent. 



MiSCELL-iNEOUS. 



There are other brands of fertilizers on the market. Some are 

 rarely, if ever, used by the farmer. 



