Ordinary humus contains such organisms in countless numbers, and it is probable that when excreta are mixed with sterile bodies, such as ashes, the necessary organisms are in part supplied by the excreta themselves, or possibly gain access from the air around.
In order that humification may take place two things are necessary:—
- 1. The matter must be tolerably dry—absolute dryness checks the process, so does excess of moisture. It is stated that about 33 per cent. of moisture is the amount with which the humifying change is most rapid.
- 2. The access of air is necessary, because the organisms which produce humification are aërobic, and, as much of the change consists of oxidation, it is evident that the free access of air is essential.
Actual Practice
It may be well to refer here to what is actually done in my garden at Andover, in Hampshire.
It should be stated that the garden is close to the centre of the town of Andover, the chief town in West Hants (a purely agricultural district), with about 6,000 inhabitants.
The garden abuts on a street and lies very low, being only two or three feet at most above the average level of the river Anton, which forms one of its boundaries.
The interest of the garden lies in the fact that it has been manured for the last ten years with the excreta and other refuse of some twenty cottages, the only stable dung which has been used having been sufficient to make a hotbed in the spring, and no more.
