Again, the House of Commons passed a stringent Act to prevent the pollution of rivers, but when, a year or so since, their own sewage arrangements were at fault, they merely constructed an ingenious apparatus to thoroughly suck the sewage out of their own premises and pass it on more effectually than before to pollute the river on whose bank their stately palace stands. What is the good of legislation without example? If the House of Commons, at some sacrifice (more fancied than real) of personal convenience, had adopted measures in accordance with the spirit of their legislation, I believe we should have been within a measurable distance of seeing the Thames once more meriting the name of silvery. A good example is better than any amount of legislation, and a good example set in high places is much needed in this matter, to which there is undoubtedly a moral side. How to alter the present arrangements in London now the houses have been almost uniformly deprived of their curtilage is very difficult. Under such circumstances “returning were as tedious as go o’er,” but I am myself inclined to think that the best solution of London’s sewage difficulty lies in the direction of cremation--certainly in the direction of decentralisation. I believe also that at the outskirts much might be accomplished by an equitable adjustment of sanitary rates, and by encouraging householders to do for themselves what no public authority can do so satisfactorily for them. But as I have dealt with this subject very fully in a paper on “The Shortcomings of Modern Sanitary Methods,” I shall say no more at present. London gets more than half its water from the Thames, and this is another reason why the sanitary outlook is not satisfactory. The system of water-carried sewage is now almost universal, the sewage ultimately taking its course along the track of the watershed. Wherever water-carried sewage is in vogue the natural watercourses must get fouled, and the fouling will be in proportion to population. The sewage may be deprived of its coarser ingredients by mechanical or chemical means, but it is not possible to believe that any of the methods of treating sewage at present in use render the effluent wholesome enough to drink without danger. The increase of population in the valley of the Thames is therefore a distinct danger to London. The following table gives the population for 1871 and 1881 of some registration districts situated in the Thames valley:--