PROCEEDINGS OF THE COTTESWOLD CLUB I35 



is of the remotest. The dilution is in the first place 

 enormous, the conditions are exceedingly unfavourable to 

 these specific bacteria as compared with the river bacteria 

 and it has been proved by actual experiment that the 

 two kinds cannot go on living side by side, and it would 

 be absurd to suppose that the river bacteria could be 

 displaced from their natural element by weakly strangers. 

 Unless the cultivating material be suitable, the bacteria of 

 disease do not multiply in it, and river water unless 

 grossly polluted with sewage material is certainly not a 

 medium suited to the development of Typhoid bacilli. 

 The evidence that we have at present goes to prove that 

 Typhoid bacilli may be expected in rivers near the mouths 

 of sewers, and that if they multiply in river w^aters it 

 is only in situations where the pollution by the material 

 in which they have been developed in the body is at 

 a maximum, and that dilution and exposure to flowing 

 water very quickly destroys them. The same thing 

 holds good of Cholera, of which however we have 

 but little experience, but one cannot suppose that Cholera 

 bacteria are at all likely to multiply through the waters of 

 our larger streams in face of the natural difficulties 

 presented. In small collections of water, how^ever, there 

 is greater danger, the pollution reaches a far greater 

 intensity, and in the water of wells and small stagnant 

 stores there is evidence to show that disease organisms 

 may multiply and continue through a prolonged existence. 

 Any water of whatever origin, that contains unaltered 

 sewage material, is absolutely unfit for drinking until 

 such material has been destroyed or removed, and pre- 

 vious to such destruction or removal its use is reprehen- 

 sible in the highest degree. Lately the subject of 

 water-borne diseases has been much to the fore, and 

 some extraordinary examples have been placed on record. 

 The Local Government Board, through their Inspectors, 

 have made many inquiries into the origin of outbreaks of 

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