1922.] 



Town Refuse as Man ike. 



687 



on the farm would be greatly relieved; but we must expect 

 these methods of conservancy to be superseded, and therefore 

 we must turn to ashpit refuse as the only important unfailing 

 source of this type of material. 



In its crude form the refuse contains a small percentage 

 of cans, bottles, etc., of no use on the farm but indeed consti- 

 tuting a nuisance. In the more progressive towns these are re- 

 moved and the material undergoes a certain amount of sorting 

 to remove coal, cinders, rags, bones, scrap metal, etc., for all 

 of which a market can be found. Thus at Falkirk, where a 

 good modern plant has been installed, the cinder amounts to 

 some 35 per cent, of the total collection : it has a calorific value 

 of 8,000 B.T.U. per lb., and after being taken out is used for 

 steam raising at the local electricity station. Whatever the 

 preliminary sorting treatment the remaining material is disin- 

 tegrated to break up the larger and coarser materials. Three 

 possibilities are then open : — 



1. Use without Modification. — The material can be offered 

 to farmers as it stands. It is in good physical condition for 

 putting on to the ground and for lightening a heavy soil. Its 

 composition, however, is not particularly good in spite of its 

 smell. Improvement is effected by enriching with a certain 

 amount of other waste matter, such as street sweepings, 

 slaughterhouse refuse, stable manure, etc.. and the final analysis 

 comes out something like the following : — 



(Ca 3 (P0 4 ) 2 ) 0.7%— 1.1% 



Potash (K 2 0) 0.3%— -0.5% 



It is sometimes the practice to compare these figures with 

 those for stable manure, but as a matter of fact the two things 

 are so completely different that no comparison on the basis 

 of analytical data is possible. In the case of stable manure it 

 is not difficult to arrive at some estimate of value from a care- 

 ful study of the analytical data, as there is the possibility of 

 ascertaining approximately what proportions of the various' fer- 

 tilising constituents have come from straw, faeces and urine, 

 these being the three components. In the case of ashpit refuse 

 it is impossible to say how much of the nitrogen comes from 

 animal or vegetable refuse (where it would have a certain value). 



Organic matter ... 

 Nitrogen... 



Phosphoric acid (P.,0 5 ) 

 Equivalent to tricalcic phosphate 



