APPENDIX. 307 
into evacuation pipes of the sewer by sypecial sphons, and. 
help to flush them. This system has been applied to the 
Hotel de Ville, to the new Guards’ barracks, to a certain 
number of primary schools, and to many private houses. 
The municipal administration proposes to apply this 
system to most of the schools, hospitals, and barracks, of 
which the sanitary condition is at present far from satis- 
factory. They hope eventually to extend the same system 
to all private houses, so as to do away with the cesspools— 
a reform already effected in many foreign cities, and 
notably in Germany. 
KR 
APPENDIX TO CHAPTER V. (p. 172). 
THE SEWERS OF PARIS AND THE PLAIN OF GENNEVILLIERS. 
The water issuing from the main sewer of the city is 
partly turned into the Seine, partly into the plain of 
Gennevilliers, and used, by a system of irrigation, for fer- 
tilizing the soil. There was some fear lest the vegetable 
mould might be saturated with fertilizing matter, but the 
presence of a special microbe was ascertained, which re- 
duces organic matter to its inorganic constituents, and 
thus adapts them to. be absorbed by plants. Schlossing 
and Muntz, who have studied this microbe, term it the 
nitrifying microbe. The same system of sewer-irriga- 
tion will shortly be applied to another place in the neigh- 
bourhood of Paris, Achéres, near the forest of Saint- 
Germain. 
