PKOCEEDINGS OF THE BOARD OF REGENTS. 347 



prejudicial to health. Observation has shown that the death rate is much greater 

 among the population along these open sewers than in streets removed but a 

 short distance from them. 



The signs of animal life visible to the naked eye in small rivers after receiv- 

 ing sewage matter consists of myriads of minute worms, characteristic of all 

 sewage water, and may be regarded as the last remains of animal life which can 

 survive in such a locality; and even these die off in summer. 



The putrescence of the organic liquids and deposits in the open sewers and 

 bottoms and beds of streams in all weathers, and the evolution of noxious gases 

 therefrom, lead to the sensible contamination of the surrounding atmosphere, and 

 consequently decreases the purity and healthiness of the air, and the discharge 

 of sewage matter into streams and small rivers pollutes the water by the mixture 

 of much organic matter in a state of active putrescence. 



Analysis gives 15 to 80 grains per gallon of suspended matter, and from 35 

 to 76 grains of dissolved matter, of the sewage of large towns. Of the former 

 about 35 per centum is organic, and of the latter about 28 per centum. The 

 organic matter consists of vegetable and animal fibre with a soluble extractive in 

 a high state of decomposition. The organic constituents give off such an abund- 

 ance of foul gases that they are a constant source of annoyance. These gases 

 consist of about 73 per centum of light carburetted hydrogen, 16 per centum of 

 carbonic acid, 10 of nitrogen, and traces of sulphuretted hydrogen, ammonia, and 

 a putrid, organic vapor that is in the highest degree offensive. 



Every gallon of sewage will discharge from 1^ to 1 J cubic inches of this gas 

 per hour, and the fermentation continues for weeks. Whenever this gas escapes 

 from privies, cesspools, or sewers, it causes disease, and finally sets up a putrid 

 form of fever which is exceedingly fatal. 



Every effort is made elsewhere to prevent the diffusion of these foetid gases 

 into the houses and public ways, while in Washington we promote the evil to an 

 incalculable extent and danger in that vast fermenting vat, the city canal. 



It follows that the sewage of large populous cities and towns can only be con- 

 ducted into large rivers near the sea, that they may not contaminate the atmo- 

 sphere, and should never be discharged into fresh-water streams used or required 

 for man or beast. 



If conducted into closed harbors or bays, they create such a deadly pollution 

 as soon to lead to the most alarming consequences. 



The magnitude of this evil, and the suddenness with which it may come upon 

 us in its most fatal form, are exemplified by the experience of London. The 

 committee asks attention thereto, as fully illustrating the evil we have to com- 

 bat in this city, and the necessity of prompt attention : 



" On the introduction of the water-closet system in London, and the abolition 

 of cesspools, with the increase of gas-works, the Thames began to give indica- 

 tions of receiving a larger quantity of decomposing matter than it could purify 

 or get rid of by the tide movement. In 1856 it became apparent in the summer 

 months that the river emitted a disagreeable stench. This became still more 

 evident in 1S57, and was obviously dependent on the increased attention paid to 

 the removal of all refuse from houses by the aid of drainage. In 1858 the stench 

 appeared with increased intensity, and especially in the neighborhood of the new 

 houses of parliament. Every one felt it was necessary to meet so gigantic an 

 evil. The river had become one elongated cesspool, and the effect upon the 

 teeming population of its banks might be in a short time of the most disastrous 

 kind. In 1858 an act was passed for preventing, as far as practical, the sewage 

 from passing into the Thames within the metropolis, giving authority to expend 

 three millions of pounds sterling to effect the object." 



This experience may very properly be received as a truthful representation 

 of what is being done in this city, and the consequences. 



The specific gravity of sewage gases is lighter than that of the atmosphere 



