124 LESSONS u; chemistry. 



from the spouts, as well as that which falls upon the yard, 

 should be conveyed away, by drains so constructed that 

 it may be allowed to flow over the adjoining fields, or 

 used to dilute the contents of the tank. The liquid from the 

 byres and stables, which has not been absorbed by the litter, 

 and also the drainage from the farm-house, should be con- 

 veyed to the tank by drains, which are readily formed by 

 inverted draining-tiles bedded in clay, and covered over with 

 boards or flags. To prevent any loss of space, the tank, 

 when placed across the manure-stead, may be covered with 

 a close wooden grating, and the dung piled upon it, by which 

 means the evaporation of the liquid will be prevented, and 

 any escaping gases absorbed by the manure. Some farmers 

 consider it necessary to cover the manure with a roof, but 

 when the yard is carefully drained, it may be dispensed with, 

 as the rain which falls upon the heap will tend to prevent 

 too rapid fermentation, and any matters dissolved out will 

 be found in the tank. 



182. The manure should be evenly spread upon the dung- 

 stead, and the sides of the heap preserved perfectly straight, 

 and care should be taken to prevent the temperature rising 

 too high. When it rises above 82 degTces of the thermo- 

 meter, it should be moderated by an application of liquid from 

 the tank. Fermentation should not be allowed to proceed 

 farther than when the straw commences to lose its consis- 

 tence. At this period it is admirably adapted to promote the 

 growth of plants, and when it is not convenient to remove to 

 the fields, some sulphuric acid, sulphate of lime, or sulphate 

 of iron, should be added to the liquid before pumping it on 

 the heap. " Farmers," says an able continental writer on 

 this subject, " often hesitate to make the necessary arrange- 

 ments to save their liquid manure, because they imagine they 

 can obtain it in very small quantity. They do not consider 

 that the little stream of liquid manure which trickles from 

 their dunghill runs during nearly the whole year, and increases 

 with every rain. With 6 or 8 horses, as many cows and 

 oxen, and 100 sheep, there may be obtained more than 200 

 hectolitres* yearly, when the arrangement to collect it is 

 made in a manner by which none will be lost. With this 

 quantity distributed in the fields, many thousand pounds 



* A hectolitre is about 22 gallons. 



