195 
100°C., obtained on evaporating the filtered water, to be 
“total matter in solution,” but I was of course aware 
that much loss arose by the decomposition of the sewage 
matter in the water into carbon dioxide at about 100°C. 
The oxygen tests were applied directly the water arrived 
in my laboratory; also the ammonia determinations. I 
do not wish to make comparisons between Wanklyn’s or 
Tidy’s methods, because both are most excellent; but 
it would appear from the curves that the first-mentioned 
method is more reliable in its indications of real sewage 
contamination than the method of Tidy. Having now 
shown the state of the Irwell and some of its Hibutaries, I 
ask. What is to be done to cleanse it or improve it ? The 
answer to this question is, “ Insist sternly upon the sewage 
of all towns and local authorities abutting on the river being 
treated in a proper manner and removed in the crude state 
from the rivers ; see that the so-called ' sewage processes ’ 
or ‘ schemes ’ of the various local authorities on the map 
appended to this paper, are thoroughly carried out, and not 
shams, as some of them are to my knowledge at the present 
time; have the powers of the Rivers Pollution Act put into 
force in a reasonable but determined manner against the 
disgraceful and selfish pollutions at present caused by manu- 
facturers on the banks of the Irwell and its tributaries, and 
at once do away with the dangerous and abominable practice 
of casting ashes and cinders upon the banks in order to be 
washed away at the first flood.” 
I know, from personal knowledge, that the Rivers 
Pollution Act is an absolute dead letter, not being applied 
at all on the Irwell, and might never have been passed. 
I must not conclude my paper without acknowledging 
the very valuable assistance I have received throughout 
this inquiry from my assistants, Messrs. A. E. Fasnacht and 
W. J. Rowley; also from my friend Mr. Cartwright, the 
