STERILIZATION 



173 



effluent flows into a river from which water for drinking is 

 obtained, and we are generally considering what measures may 

 be desirable to lessen dangers so arising " (p. 29). It was 

 hoped that the Commission would have followed by informa- 

 tion as to processes of destroying micro-organisms or steriliza- 

 tion of effluents on the large scale, but although evidence on 

 the subject was given before them by Drs. Klein, Thresh, 

 myself, and others, and one of their references was as to what 

 remedies were practical and available for injuries caused by 

 sewage, sterilization finds no further mention in their conclu- 

 sions. The nearest approach is in their Fourth Report, vol. i., 

 p. 20, under " Remedies Suggested," where the proposal that 

 all sewage should be purified is met by two objections : non- 

 necessity, and non-efficiency. 



N on-necessity y because there are " many cases where shell-fish 

 are not concerned . . . and to require purification in all cases 

 would lead to the waste of large sums of money." 



Non-efficiency, because they consider that no treatment at 

 present in use can be relied on as safe. 



They seem to have ignored the point that sterilization of a 

 partially purified effluent when jiecessary was possible, and had 

 been achieved in several places without ruinous expense. And 

 yet the keynote to this idea had been struck shortly before in 

 the Report of the Local Government Board for Ireland, 1903, 

 p. 7, in the phrase, " Short, however, of the sterilization of 

 sewage effluents discharging in the immediate vicinity of shell- 

 fish beds, no other form of treatment at present in use is likely 

 to be effectual in destroying or removing, although it may 

 succeed in reducing, the number of pathogenic germs." 



Owing to the foul condition of rivers near or within large 

 towns, vigorous attempts have been made to disinfect them 

 with chemicals, or to add the latter to the sewage, with the 

 object of removing or neutralizing free ammonia, compound 

 ammonias, and sulphuretted hydrogen, and so to render the 

 liquids almost inodorous for the time, and to hinder further 

 decomposition of the organic matters. Any acid or acid salt 

 would neutralize the ammonia ; many metallic solutions would 

 absorb sulphuretted hydrogen, and also precipitate much of the 

 organic matter, and a clear effluent without much odour and 

 almost colourless would be obtained. But several difficulties 

 occur : — 



I. It is a mistake to suppose that the odorous ingredients 



