1883.] Observations on Polluted Waters . 389 
there was no natural process by which their purification 
could be effected within the course of any British stream. 
I come now to the second part of my subject : can fish 
live in sewage ? It is somewhat curious that the affirma- 
tion should still be maintained. Perhaps the very first 
impulse to the movement for preventing the pollution of 
rivers in Britain was due to the observation that the contrary 
is the case. Said the riparian proprietor to the people of 
the town next above him on the stream, “ Your sewage is 
destroying my fish,” — and this destruction has been one of 
the reasons why in such cases injunctions for the abatement 
of the nuisance have been issued. It will not do to say that 
the fish are killed not so much by sewage, properly so called, 
as by the waste waters of various factories. True lime, the 
hypochlorites, sulphate of soda, coal-tar products, and a 
long string of other bodies which find their way into our 
rivers, have played sad havoc among fish. But whoever 
will make careful inquiry will find that fish have also dis- 
appeared, though more gradually, where nothing but sewage 
— in the strict sense of the term — has found its way into the 
rivers. I have seen (“Journal of Science.” 1881, p. 144) 
fishes darting about in the Thames at the spot where the 
Kingston sewer then opened, and I have heard that the 
locality was on this account much frequented by anglers. 
But I was also told that the fish caught in such localities 
enters into putrefaction with unusual rapidity. Hence, I 
think, it may be fairly argued that such fish are in a morbid 
condition, and that the circumstances to which they are 
exposed must sooner or later bring on their destruction, as 
we in faCt find is the case in rivers where sewage pollution 
is great. As long as the volume of sewage is but small in 
comparison with the bulk of clean water, they will survive, 
and will visit the sewer outfall for feeding purposes, attracted 
by the larvae of various kinds and by the particles of human 
food brought down by the impure water. But we have no 
evidence to show that this sewer haunting is conducive to 
their health or multplication. On the contrary, if we only 
observe carefully, we find that it is destructive to them, some 
species resisting longer than others. That excrementitious 
matter, per se, is avoided by fishes we have observations to 
prove. An intelligent Parisian ravageur states, in the 
“ Moniteur Scientifique Quesneviile,” that fishes avoid any 
particularly offensive discharge of matter from the mouth of 
the sewer, and hide themselves among the weeds till the 
nuisance has passed. I have observed from time to time, 
and in different places, shoals of minnows playing about th$ 
