214 Micruhic Life in Seivcr Air. 



te raised much beyond that which is ordinarily found in proper 

 sewers, with an abundant water supply. I mentioned, when 

 speaking of sewer flushing, that this process must be frequent at 

 certain times, when temperature is higher than usual. If at 

 any time the temperature in this country should be continually 

 high for a month or six weeks together, so that the temperature 

 of the London water should be kept above 65 degrees for a 

 month, London may prepare for a tremendous outbreak of 

 typhoid in the succeeding autumn. It requires a continuously 

 high temperature for probably a month to develop typhoid spores 

 in the drinking water as at present manipulated at the filter 

 works of the water companies. That season will come some 

 day with the usual result, " panic," and consequent loss. For 

 the si^me reasons, unless sewers have their temperature perma- 

 nently raised for some time, there is no danger from benign 

 germs being replaced by malignant ; but I believe that it is pos- 

 sible for the continuous discharge of hot water so to raise the 

 temperature of a drain-pipe, that it may be a hidden source of 

 danger, and that such continuous discharges of hot water from 

 manufactories may be dangerous in badly-constructed sewers, 

 though an excessive heat, such as is experienced on a sunny day, 

 destroys bacteria. But if sewers are well and truly laid ; if the 

 pipes are smooth inside and have been properly jointed ; if they 

 flush clean, and are properly flushed at intervals, depending 

 upon the temperature of the sewage, then there is no real 

 danger from the admission of hot water into sewevs. 



I think I have dealt with the four points to which I have drawn 

 attention, and I will conclude what I have to say on this subject, 

 by stating that the greatest danger from drains is not in the public 

 sewer, but in the house connection, and in the private drains 

 laid by speculative builders. These are only occasionally used, 

 they become all but dry at frequent intervals ; and if they are 

 not as clean as a back kitchen sink ought to be, they will, in spite 

 of all precaution, occasionally produce sewer air. They must be 

 ventilated even more perfectly than the public sewers, and so cut 

 off from all direct communication with the house, that it shall 

 be absolutely impossible for any of tbe products of decomposition, 

 if they arise, to find their way inside the dwelUug, and carry 

 living, growing germs with them. If these arrangements are 

 carried into effect, those living in such houses may defy disease 

 germs and live in perfect safety from their atticks ; and, in the 

 words of the Psalmist we may say : — 1. " Thou shalt not be 

 afraid of any terror by night, nor for the arrow that flieth 

 by day ; nor for the pestilence that walketh in darkness, nor for 

 the sickness which destroyeth in the noonday. 2. A thousand 

 shall fall beside thee, and ten thousand at thy right hand, but it 

 shall not come nigh thee." 



