PIONEER WORK 163 



this to be so iu 1865, naming spirilla, vibrios, and a " protococcus " as 

 the organisms in question. Then in 1881 M. Louis Mouras, of Vesoul 

 (Haute-Sadne), published an account of an hermetically-sealed, in- 

 odorous, and automatically discharging cesspool, in which sewage was 

 anaerobicaUy broken down by " the mysterious agents of fermenta- 

 tion." The effluent, a homogeneous and scarcely turbid fluid, was 

 produced in a tolerably short time and without any addition of 

 chemical ingredients. It was surmised that the agents of fermenta- 

 tion might possibly be the " anaerobes of M. Pasteur." This, it would 

 seem, is the first record we have of the treatment of sewage by simply 

 allowing Nature to fulfil her function by means of bacteria. 



The next step — ;and indeed as regards the problem in England the 

 first step — ^in the new bacterial treatment of sewage was inaugurated 

 by the workers (Jordan, and others) under the State Board of Health 

 of Massachusetts, who have carried out a laborious series of experi- 

 ments upon sewage purification during the last fifteen years. The work 

 undertaken at this station may be briefly divided into three main 

 classes: first, purification of unfiltered crude sewage by means of 

 intermittent filtration through sand filters ; secondly, rapid filtration 

 of sewage, from which a certain amount of sludge has- been removed, 

 by different methods and through different materials ; thirdly, purifi- 

 cation by dependence upon rapid oxidation or burning of sludge 

 either by forced aeration or other method of introducing air into the 

 filter. Various methods have also been devised with the object of 

 getting rid of the insoluble matter in sewage. The result of this 

 extremely valuable work by the Massachusetts Board clearly demon- 

 strated the accuracy of the fundamental principle that on prepared 

 beds or "intermittent downward filtration" the contained bacteria 

 were the potent agency.* 



Whilst this work opened up a new prospect for the bacterial 

 treatment of sewage, it still left the question in an experimental stage, 

 and then it was that Scotfc-Moncrieff, Dibdin, Cameron, Ducat, and 

 others carried forward the work.f It was in 1892 that Mr Scott- 



* In his evidence before Lord Brarawell's Commission, 1883, Dr Sorby had 

 pointed out that the destruction of the organic sewage matter in the Thames was due 

 to bacteria, and that it was only when these were unable to exert their functions to 

 the full extent by reason of deficient aeration of the water that putrefaction set in. 

 t The following general classification will serve to show the nature of the pro- 

 cesses adopted by various workers : — 



Closed septic tank and contact beds. 



Open septic tank and contact beds. 



Chemical treatment, subsidence tanks, and contact beds. 



Subsidence tanks and contact beds. 



Contact beds alone. 



Closed septic tank followed by continuous filtration. 



Open septic tank followed by continuous filtration. 



Chemical treatment, subsidence tanks, and continuous filtration. 



Subsidence tanks followed by continuous filtration. 



Continuous filtration alone. 



