54 PLANT PRODUCTS 



partnership with them. The chemical fertilizers will supply 

 the quick-acting and stimulating part, and the farmyard 

 manure will supply the more lasting and soil-improving 

 part. With the present lack of potash manuring, farmyard 

 manure forms the chief source of that element in farming. 



The Utilization of Sewage.— The primitive system 

 of every man to his own land soon breaks down with 

 large populations. Simple closets are very unsatisfactory, 

 since flies communicate disease, and even smells are lowering 

 to health. The earth closet is a great improvement if enough 

 dry earth can be obtained . The resulting material, if removed 

 to the garden, provides a useful fertilizer, but for towns the 

 weight of the soil is an insuperable objection. Under the 

 systems where the sewage is allowed to accumulate in cess- 

 pools great nuisance arises. A better system consists in 

 removing all household refuse in carts at night. This 

 mixture, known as " night soil,'' or " Scavenger," is carried 

 to outlying farms, and either put direct upon the soil or 

 put into trenches which have been previously dug. Farmers 

 contract with municipalities to supply themselves and 

 neighbours. Under these systems a rotation is adopted on 

 the farm to suit periods of excessive manure, followed by 

 periods of no manure at all. The details of such management 

 on the farm will depend largely upon the local requirements, 

 but the system has been found to work passably well when 

 on a comparatively small scale. A more elaborate and 

 industrialized system is that generally known by the French 

 name of '' Poudrette," where the night soil is taken to a 

 factory and is there mixed with a suitable proportion of 

 ashes and soil, allowed to ferment over one or two years, 

 and then sold to the neighbouring cultivators. Such 

 Poudrette contains about 20 per cent, of water, 10 to 15 per 

 cent, of organic matter, J to i per cent, of nitrogen, and J 

 to I per cent, of phosphoric acid. Such a factory must be 

 situated well away from the town. In very industrial 

 districts the night soil collected may be taken to a factory 

 and dried, and the grease extracted by petroleum spirit, 

 the resulting material being supplied to the farmers in the 



