30 BOARD OF AGPJCULTUEE. 



the process of filtration thus established, or by any other 

 mechanical filtrage. A solution of morphine loses no 

 strength because of filtrage. Again, most of our city 

 vaults have overflows into a neighboring sewer, and, 

 drenched with floods of water, the soluble matter is washed 

 away, leaving only a worthless sludge. The long intervals 

 between the periods of emptying are sufficient for com- 

 plete decomposition of the nitrogenous matter. The am- 

 monia is lost in the atmosphere or carried away by the 

 overflow. 



To-day St. Petersburg, Odessa, Vienna, Rome, Naples, 

 Brussels and London are perplexed to knoAv what shall be 

 the final disposal of the detritus of these great cities. It is 

 but a few years since London completed her great metro- 

 politan sewer to discharge at ebb tide twenty-one miles 

 below the city in the maritime Thames and Avhere the river 

 is about half a mile wide. It has cost the city over twenty- 

 one million dollars. Its successful opening was heralded 

 throughout the world as a great triumph of engineering. 

 It has taken but a short time to demonstrate its failure. 

 She now learns that sewao-c is not oxidized in water, it is 

 not carried to sea by the tides, it is not diluted to an extent 

 sufiicient to render it innoxious, but it is precipitated above 

 and below the mouth of the sewer, and a great cry of indig- 

 nation now comes from the inhabitants living along the 

 banks of the river. During the past summer twenty-two 

 tons of chloride of lime have been used each day to abate the 

 stench. Boston is beginning to realize the folly of imitating 

 this system of disposal, for already there is complaint along 

 the south shore in the vicinity of Moon Island. 



Torquay and Brighton, draining directly into the English 

 Channel, have experienced similar results, and their systems 

 are pronounced failures. 



Washington is agitated over the malaria supposed to be 

 caused by the deposit of sewage on the Potomac flats ; 

 Philadelphia by sewage in the Schuylkill ; Baltimore by a 

 system discharging into the " basin," and threatening 

 destruction to the oyster beds of the Chesapeake. Chicago 

 empties her sewage into her source of water supply. With 

 a south wind and high water in the Chicago River, we are 



