ANNIVERSARY ADDRESS. 25 



beds, were such a success that chemists and sanitarians could no 

 longer afford to ignore the merits of the method ; hence experi- 

 ments were made in a number of places in the Empire, Sydney- 

 included. In the meantime the London County Council had 

 determined to severely test the new, or rather old, biological pro- 

 cess, and in the hands of Drs. Clowes and Houston such gratifying 

 results were obtained that I make no apology in giving you an 

 account of the treatment of the crude sewage of the City of 

 London. 1 These two gentlemen are chemist and bacteriologist 

 respectively to the London County Council, and great interest is 

 now being taken in their results, inasmuch as they are both inde- 

 pendent scientific men, having no patent-right interest in the 

 process. Their attention was directed to the purification of 

 London's crude sewage as it is delivered at the Barking and 

 Crossness Outfall Works. 



A bacteriological examination of the sewage showed that 

 between three and four millions of micro-organisms are present 

 in one centimeter cube of the crude sewage, their rate of propaga- 

 tion or growth being from sixteen to seventeen millions per 

 twenty-four hours. They consist of 2 : — B. Enteritides sporogenes; 

 B. Coli communis; B. mycoides; B. subtilis; B. mesentericus; 

 Sarcince Yeast-cells, Saccharornyces, sp.; Moulds; B. Fluoresceins 

 liquefaciens; and other Protean forms, vaguely known in the 

 elder Frankland's time as the 'sewage fungus.' 



It is shown that the putrefaction of sewage may proceed by 

 aerobic bacteria under aerobic conditions; by anaerobic bacteria 

 under semi-anaerobic conditions; and by strictly anaerobic bacteria 

 under strictly anaerobic bacteria. 



Dr. Clowes abandoned all likely complications arising from over- 

 elaboration of apparatus, doing away with the shallow trays used 



1 Bacterial Treatment of Sewage (Second Eeport) by Dr. Clowes and 

 Dr. Houston. London: P. S. King and Son, Great Smith-street, Victoria- 

 street, Westminster. 



2 Filtration of Sewage — Eeport on the Bacteriological Examination of 

 London Crude Sewage by Dr. Frank Clowes (First Eeport). London: 

 P. S. Kiog and Son, Great Smith-street, Victoria-street, Westminster. 



