146 PROCEEDINGS OF THE COTTESWOLD CLUB 



origin discharged into the river, as related to the amount 

 of water in the river, supposing at the same time that, 

 notwithstanding it? organic nature, it suffers no destruction! 

 and the river is at its lowest, even so, its relative weight 

 is infinitesimal. When we come to consider the un- 

 deniable fact that this organic matter is destroyed in the 

 water with great rapidity, so that after a very few miles 

 flow from the place of reception as we have plenty of 

 evidence to show, the material is entirely destroyed, the 

 degree of pollution becomes lessened to a vanishing 

 point. No doubt it is quite possible to pour more sewage 

 into a river than can be destroyed; such was the case 

 when the whole of the London sewage went untreated 

 into the Thames, and in such a case we have all the 

 dangers of a permanent pollution ; but no such condition 

 obtains anywhere in the Severn. I have satisfied myself 

 by my own examinations and analysis, that all the sewage 

 received by the Severn makes no appreciable difference to 

 the water at Tewkesbury. Dr Swete, the Worcestershire 

 Analyst, has proved to me, by the result of his examina- 

 tions, that the process of destruction of the Worcester 

 sewage is complete five miles below Worcester. I have 

 satisfied myself of the same thing, by analyses and bac- 

 teriological examination, having collected water for the 

 purpose on the same day above Worcester and at points 

 below the town at increasing distances. The bacteria in 

 the water of the river increase in numbers opposite and 

 immediately below the town, but three or four miles 

 lower down have come back to their normal numbers. 

 The oxygen in the water, as Dr Swete has shown is at 

 saturation point above Worcester, and is reduced opposite 

 and below the town by the oxidation of the organic 

 matters discharged into the river; but five miles below 

 Worcester the water has returned to its nominal satura- 

 tion by oxygen, and also to its nominal yield of ammonia. 

 The organic material brought in by the little slow- 

 flowing river. The Perry, notwithstanding that this comes 



