278 



two-thirds of the lime of the bone from the phosphoric acid, which 

 remains united with the other third, forming a superphosphate, bi-, 

 phosphate or mono-calcic phosphate, which substance is perfectly soluble 

 in water, and is called soluble phosphate. The sulphuric acid uniting 

 with the lime forms a sulphate of lime, (gyjisum, or plaster,) So that in 

 every heap in which a su])erphosphate has been made there is always 

 an amount of sulphate of lime (plaster) formed, and the plaster forms 

 the greater portion of the whole mass. 



The bones which are used for making superphosphates by manufac-' 

 turers, or which may be had by farmers, are found in the following con- 

 ditions: ]. Bone dust or ground bone. 2. Boiled or steamed bones. 

 3. Bone ash of sugar retiueries. 



1. Bone dust. — Before the bones are crushed they are now generally 

 boiled for the sake of the fat, which is sold to the soap boiler. It is of 

 no value as a manurial agent, but is rather deleterious, coating the bone 

 and protecting it from the action of the acid, and it would be advisable 

 for the farmer when possible to boil the bones. 



2. Boiled or steamed hones. — Bones are steamed for the purpose of re- 

 moviiig gelatine or animal matter of the bone for the purpose of con- 

 verting it into glue. The effect of steaming on bone is therefore to 

 deprive it of some of its organic matter, but it must not be supposed 

 that the whole of the organic matter is removed ; a considerable quan- 

 tity remains, and some ammonia can always be found iu such bones 

 when decomposing. A reference to the analysis shows that not more 

 than live or six per cent, of organic matter has been extracted from the 

 bone. 



3. B<me ash. — If bones are burned in contact with the air, the greater 

 part of the carbon is driven otf with the other combustible parts of the 

 tioue. To avoid this result, which would render the ash worthless for the 

 use of the sugar refiner, the bones are charred in heated iron cylinders, 

 out of contact with the air, by which only a portion of the animal matter 

 is burned off. A large amount of finely-divided charcoal remains, mixed 

 with the bone earth, giving the valuable properties to the bone ash. It 

 has become a great deodorizer and antiseptic, and capable of condensing 

 gases within its pores, by which means it retains both the ammonia and 

 nitrogen of the soil and the manure. The black color of the bone ash 

 is due to this charcoal. 



(■.oelcker.) 



Bone 

 dusit. 



Moisture 12. OC 



Organic matter* 31. 12 



Phosphates of lime and magnesia, (bone earth) I 49. 54 



Carbonate of lime 4. 99 



Magnesia and alkaline ealts, (chiefly common Kal!) 1-91 



Sand -38 



Total 100.00 



* Containing nitrogen 3. 69 



Equal to ammonia -1. 49 



(AnderBon.) 



Steamed 

 bone. 



8. (:6 

 2.j. 45 

 60.48 



3.25 

 .43 



2. .33 



100. 00 



1.84 

 2.24 



Bone ash. 



6.10 

 5. 05 

 79. 20 

 4.05 

 .15 

 5.45 



100. 00 



One hundred pounds of boners, ground, crushed, or dust, (not burned,) 

 require forty pounds of sulphuric acid, (vitriol.) This quantity, if acting 

 solely on the bone phosphate, would remove two-thirds of its lime ; but, 

 as tllere is ahvavs some carbonate of lime present, this is first acted on 



