I might have added to the diagram a third curve showing the produce 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 comprising the forty years, the value of the organic matter becomes very manifest. Thus the yield for each decade was with

Farmyard dung44·951·550·051·6
Artificial manure48·749·442·841·5
Unmanured22·217·513·712·6

It will be observed that the yield from artificial manuring only exceeded the yield from the farmyard plot 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 agriculturists 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. Our 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 (see page [65] and figs. [22] and [23]).

Now no water can possibly enter the well, except through the bottom. The water in it is clear and bright, and since its construction no mud has collected on the bottom. The sides of the pipes also remain absolutely clean, so much so that when, in 1895, I showed this well to a party of scientific friends, some of them dropped a hint that it had possibly been scrubbed in honour of their visit. This, however, was not the case.

The water from this well has been examined three times chemically, with the result that it has been pronounced free from organic impurities, and three bacteriological examinations have been made, with the result of showing a bacterial purity which is quite exceptional. The last examination was made by Dr. Cartwright Wood in November 1895, and showed a very high degree of bacterial purity. The water was specially examined by Dr. Wood for the presence of Bacterium Coli commune, but with negative results. Dr. Wood writes: 'The results are exceedingly satisfactory, and I must admit surprised me very much.' A surface-well on this pattern has lately been constructed in a village near Andover, and the results, as far as the appearance of the well and water is concerned, seem to be entirely satisfactory.