-^28 Abstract Report of Arjricultural Disci/ssjous. 



almost all declared that in their oinnion the difficulties attending" tho 

 systematic application of sewage to arable land are so great that it is 

 only ajiplicable on any comprehensive scale to grass. 



Table II. 



Ammoxia per Gallon, and estimated Y:iluc of the Coxstituexts in one Ton of 

 Sewage at dillerent Dilutions, reckoning 12i- lbs. of Ammonia per Hiad 

 per Annum from all Sources. 



Ammonia f- . n^ 



per Gallon. , ^ "l"e per Ton. 



If CO tons of fluid per head per annum 



70 ,, ,, ., 



80 ,, ,, ,, 



90 ,, ,, ,, 



100 ,, ,, ,, 



Ilofmann and Witt — mixed sample of dry weather"! 



sewage from Savoj'-street sewer / 



The same if diluted witli two-thirds its volume of) A-n-^ 



rainfall and subsoil water J, '^ 



Grains. ' d. 



6-51 1-67 



5-58 

 4-S8 

 4-34 

 3-91 



8-21 



1-43 

 1-25 

 1-11 

 1-00 



2-11 

 1'27 



Baron Licbig has, indeed, expressed a different oi)inion, and I ^^^ll 

 give you his exact words, because I am going to niake some remarks 

 on his views. Baron Liebig is a great chemical authority, he is a very 

 great man, and his words deserve careful attention. Ho says, " Tho 

 full value of sewage and of its sei)arate constituents can only be got at 

 when it is employed on arable land." He then goes on to show why 

 sewage cannot be applied jiropcrly on grass-land. He assumes first of 

 all that on sandy soils, such soils as it is projiosed should receive the 

 sewage of London — I mean the Maplin Sands — you would require 

 to jiut on twelve times as much of the constituents in sewage as you 

 coiild take off in a crop ; for example, that if you wanted to get a crop 

 of 4 tons of hay, you must put on the land the ingredients of 48 tons 

 of hay ; after which, he says, that in order to take off 4 tons of hay 

 annually, you must put on the land 2430 tons of sewage per acre. This 

 being the quantity which he considers will contain the ingredients 

 removed annually by the 4 tons of hay. Now, I should like to ask 

 any agriculturist present whether if you put on the ingredients of a 

 crop you can take them all oft' in this way V For instance, if you apply 

 1 cwt. of guano, can you at once take off 11 bushels of wheat and 

 its proportion of straw ? The manfacturers of ai'tificial manures will 

 siipi:)ly you with tlie ingredients of a bu.shel of wheat, including 

 ammonia, for a shilling. If you could take off a bushel of wheat 

 directly the ingredients were applied, fanning would indeed be a very 

 good business, and the farmer would then have no difficulty in selling 

 wheat for 5s. per bushel ; but on this point theory says one thing and 

 practice another. 



I am not surprised that the Lord Mayor of London, and the Com, 

 Coal, and Finance Committee of the City should be pleased at the value 

 placed upon this sewage by Baron Liebig. They say, " We are losing 



