194 



Fertilisers 



[PT. Ill 



to lawns on thin dry soils: it is also useful in farm 

 practice. Care should be taken that it is groiuid suffici- 

 ently to reduce the bone to a fine state. It must be got 

 into the land quickly or it may be taken by birds. 



Meat guano or meat meal, greaves 



This is prepared from tankage from the Argentine, 

 and some also from waste meat, condemned meat, refuse 

 from slaughter houses, etc. It is first heated by steam 

 to extract some of the fat and then subjected to pressure 

 to remove as much more as possible this process being 

 adopted because of the high commercial value of fat for 

 the soap and candle industries. The resulting cake is 

 then broken up, dried, separated by shaking from 

 foreign matter such as iron, glass, and is finely ground. 

 Some of the fibrous material which still remains can 

 only be disintegrated after treatment with sulphuric 

 acid. 



Some bone is always present, and definite quantities 

 are added in certain cases to bring the composition to 

 a uniform grade. The composition of various grades is 

 as follows : 



Greaves is the waste material sent out by soap boilers 

 and others ; it is of substantially the same nature as meat 

 guano, but not being a definitely manufactured manure 



