ANIMAL MANURES. 1 1 1 



is permitted to flow away into the sewers. The solid matter 

 thus deposited, when it has acquired sufficient consistence to 

 be shovelled out, is collected and dried, by exposure to the 

 air under sheds. This manure is termed poudrette, and 

 contains, in 100 parts, about 1*8 parts of ammonia. By 

 this method, it is evident much of the valuable matters of the 

 manure is lost, as a considerable proportion of its ingredients 

 are soluble in water, and must be carried away in the liquid. 

 There is also a great loss of ammonia during the drying, and 

 the volatile gases evolved by the decomposition of the 

 organic matters contained in it decrease the amount of its 

 fertilizing ingredients so much, that this method of treating 

 excrement has been justly condemned by the leading agri- 

 culturists of France. In England, within the last foui* or 

 five years, the contents of the water-closets and cess-pools 

 of London, and some other cities, have, to some extent, been 

 purchased by fanners, and are removed, in their natural 

 state, in waggons, constructed for the purpose; but, as the 

 offensive odour of the manure has interfered with the general 

 adoption of this plan, various methods have been tried, both 

 to remove its nauseous smell, and to convert it into a more 

 portable form; and, at the present time, several companies 

 exist, which prepare manures from night soil and urine, by 

 mixing them with gj-psum, animal charcoal, and other 

 substances. 



159. Among these compounds, one, sold under the name 

 of urate, has been highly recommended as a valuable fertiliser. 

 It is said to be prepared by mixing bunit gypsum with urine, in 

 the proportion of 1 Olbs. of gypsum to seven gallons of urine, 

 and, after the solid matter has settled down, the liquid is 

 drawn off. The manure so prepared contains the phosphoric 

 acid of the urine, in combination with the lime of the gypsum, 

 and also a small portion of organic matter. In addition to 

 gj^psum, some manufacturers of m-ate add to the excrements 

 animal charcoal, which must add considerably to the value of 

 the manure. Judging, however, from a sample which was 

 lately examined in my laboratoiy, I do not consider it worth 

 the price at which it is usually sold to the farmer, as all the 

 valuable ingredients contained in it could be purchased, at a 

 cheaper rate, from the manufacturing chemist. 



160. At present, in England, considerable attention is 

 ducted to the application to agricultural purposes of the sewage 



