1896.] on the Circulation of Organic Matter. 167 



Taking the average of tlie forty years, it will be found that the pro- 

 duce of the manured land averaged 49 bushels per acre per annum, 

 while the unmanured land gave only 16^ bushels. 



I might have added to the diagram a third curve showing the pro- 

 duce of that plot of ground which, of all those manured with artificials, 

 gave the highest yield. The yield of this plot for the whole forty years 

 averaged 46 bushels, or only 3 bushels short of the average yield of 

 the plot treated with farmyard manure. If, however, we take the 

 average yield of the three plots for each of the four decades compris- 

 ing the forty years, the value of the organic matter becomes very 

 manifest. Thus the yield for each decade was with 



Farmyard dung .. 44*9 51-5 50-0 51-6 

 Artificial manure .. 48-7 49-4 42-8 41*5 

 Unmanured.. .. 22-2 17-5 13-7 12-6 



It will be observed that the yield from artificial manuring only 

 exceeded the yield from the farmyard jilot in the first decade, when it 

 showed an excess of 3 • 8 bushels. In the other three decades it was 

 deficient by 2*1, 7*2, and 10*1 bushels. 



The deficiency of the unmanured plot in each decade, as compared 

 with the farmyard plot, was 22-7, 34-0, 37-3, and 39-0. 



These figures are very convincing, and, as practical agriculturalists 

 seem to be now agreed that farming is hopeless without an adequate 

 amount of live-stock to furnish dung, no more need be said upon this 

 head. 



But is there no danger in using organic refuse, which may be 

 infective and dangerous, as an application to the land ? To this I 

 should say emphatically " No," provided it be put in the upper layers 

 of the soil, and the soil be tilled. Oiu* organic refuse, when allowed to 

 putrefy in water, and to trickle under pressure to our wells, or run 

 direct into our sources of drinking water, has turned millions of 

 pounds into the pockets of members of my profession, but when 

 rationally used as a top dressing for the well-tilled soil, it has never, 

 that I am aware of, produced any harm. 



I have tried to investigate this matter. Some five years ago I 

 constructed a well five feet deep in the middle of a garden which is 

 plentifully manured with all that is most loathsome to our senses. 

 This well is lined to the very bottom with concrete pipes, further 

 protected by an external coating of concrete ; the junctions of the 

 pipes are securely closed by cement, and there is a good parapet and 

 efficient cover. 



This well is shown in plan and section in the diagram, which I 

 will throw upon the screen (Figs. 2 and 3). 



Now no water can possibly enter the well, except through the 

 bottom. The water in it is clear and bright, and since its construc- 

 tion no mud has collected on the bottom. The sides of the pipes 

 also remain absolutely clean, so much so that when, last summer, I 



