The President's Address. By G. S. Woodhead. 213 



■oxidation of any oxidizable matter was rapidly effected by the 

 hypochlorous acid. We found, moreover, that it was possible to 

 obtain from the hypochlorous acid contained in ordinary "chloride 

 of lime" or " chloro-hypochlorite of lime" (bleaching powder) not 

 only the same but far more powerful bactericidal and oxidizing 

 effects, in that the electrolytic fluid contained only a comparatively 

 small amount of the hypochlorous acid, a substance in which 

 bleaching powder is so rich — 33 p.c. of chlorine and a proportionate 

 amount of oxygen. Using what we thought were weak solutions 

 of this bleaching powder — some four or more parts of available 

 chlorine per 100,000 of water or sewage — we obtained what were 

 then considered most marvellous results in the way of bactericidal 

 or sterilizing action. Indeed, we became almost afraid of our 

 results, they seemed to be too good to be true, and we thought that 

 there must be some underlying fallacy which had, somehow or 

 other, escaped our observation ; but although we were averse to 

 pushing the results of our experiments to their logical conclusion, 

 we satisfied ourselves that Professor Delepine, who had drawn 

 attention to the wonderful disinfectant action of comparatively 

 weak solutions of bleaching powder, was by no means overstating 

 his case. 



About this time I was asked by the authorities at Maidstone 

 to undertake the sterilization uf the whole of their reservoirs and 

 water-mains. There had been a severe outbreak of typhoid fever 

 in the town, and although no connexion between the outbreak 

 of typhoid fever and the contamination of the water-supply 

 could, at first, be traced, the authorities held, and very rightly, 

 that precautions should be taken to cut out every possible source 

 of infection (it was afterwards found that in all probability 

 the water was infected, but from a source other than any sug- 

 gested at the time of the outbreak of the epidemic). It was, 

 of course, possible to sterilize the contents and walls of the 

 whole of the reservoirs and water-mains, but in my ignorance 

 I used a solution of chloride of lime at least 100 times as 

 strong as was necessary. However, the desired object was 

 attained, and, at a later date, when it was found necessary to 

 sterilize the water derived from an infected river, during an out- 

 break of typhoid fever in Lincoln, Dr. Houston recommended the 

 use of hypochlorous acid, this time, however, combined with soda 

 instead of lime, as the sterilizing agent. The results obtained were 

 excellent, but the expense was somewhat greater than if" chloride " 

 or hypochlorite of lime had been used. It was claimed that the 

 taste imparted to the water by the hypochlorite of soda was less 

 marked and less objectionable than that given by hypochlorite of 

 lime. For some time the matter remained in abeyance in this 

 country except for contributions to the subject made by Professor 



