Closed septic tanks and contact beds. Open septic tanks and contact beds. Chemical treatment, subsidence[6] tanks and contact beds. Subsidence tanks and contact beds. Contact beds alone. Closed septic tank followed by continuous filtration. Open septic tank followed by continuous filtration. Chemical treatment, subsidence tanks, and continuous filtration. Subsidence tanks followed by continuous filtration. Continuous filtration alone. The Commissioners do not say what these safeguards are, in fact they state that no general rules concerning them can be laid down, and that in the case of these artificial processes it is necessary to consider every case on its own merits. The next point dealt with is the bacteriological quality of effluents, and here the Commissioners observe: “We find that, while in the case of effluents from land of a kind suitable for the purification of sewage there are fewer micro-organisms than in the effluents from most artificial processes, yet both classes of effluents usually contain large numbers of organisms, many of which appear to be of intestinal derivation, and some of which are of a kind liable under certain circumstances at least to give rise to disease.” No particulars of effluents from sewage farms are given, and later on it will be shown that this conclusion of the Commissioners is not in accord with the results published up to now and available concerning the bacterial purity of effluents from land treatment. The report concludes with some remarks on rivers pollution. The Commissioners state that it is of the utmost importance to provide the simplest possible means for adequately protecting all rivers, and they think that this subject is of such grave importance “as to demand the creation of a separate Commission or a new department of the Local Government Board, which shall be a supreme Rivers Authority, dealing with matters relating to rivers and their purification, and which, when appeal is made to them, shall have power to take action in cases where the local authorities have failed to do so.” Summing up the observations on the practice of sewage treatment, it may be said that as a result of their extended inquiries, the present Royal Commissioners have at the end of the century re-established land in its position as the first and only natural method of sewage purification, beside which they have recognised artificial (biological) treatments as being under proper safeguards admissible for the purification of sewage. Before concluding this portion of the observations, it is necessary to mention the valuable work done by Mr. Scott-Moncrieff and Mr. Cameron, who, contemporaneous with Mr. Dibdin, but quite independently, had experimented with sewage and evolved their own artificial methods of sewage treatment.