At Hanover a set of interesting observations has lately been made, on tanks 246 feet long, with a view to ascertaining the most advantageous rate of flow. With a velocity of 9·44 inches per minute, 62·7 per cent. of the suspended organic matters were precipitated, with a velocity of 14·17 inches per minute 61·7 per cent. were deposited, and with a velocity of 35·43 inches per minute 57·3 per cent.; from which figures it will be clear that there is not much difference in the result on the suspended matters between these velocities. Against these results must be placed the results obtained with septic tanks, where, as has frequently been stated, a velocity of 1 inch per minute and a sojourn of twenty-four hours in the tank may be expected to lead to a deposition of about 60 per cent. of the suspended matters. [Sidenote: Reduction of cost.] Where, therefore, a previous septic treatment of the sewage by anaerobes is not necessary, it is clear that the substitution of ordinary settling tanks for septic tanks will be accompanied by a very considerable reduction of cost. VIII. CONCLUDING REMARKS. Since the foregoing observations were penned, the Chairman of the Royal Commission on Sewage Disposal has delivered a very interesting inaugural address, in August last, at the Congress in Exeter of the Institute of Public Health, to which attention ought to be drawn at this point. According to _The Times_ he is reported to have stated as follows: “He regretted that he could not give some idea of the probable date at which the Commission would issue its final report and recommendations. They would soon, he hoped, be able to publish the results of a prolonged investigation into the treatment of sewage on land; and their experts were now making elaborate parallel examinations of some of the processes of filtration by artificial means. But he feared that they would ultimately be obliged to bring their proceedings to an arbitrary close; for, however much they could learn, he was quite certain they could never come to a point at which they could say there was nothing more to be learned. The subject was inexhaustible.” These very guarded observations are almost in direct contrast with the very positive assurance of some enthusiastic supporters of artificial treatments, who a year or two ago did not hesitate in proclaiming throughout this country that the panacea for all sewage difficulties had been discovered, and that the investigations of the Royal Commission were a mere matter of form and a foregone conclusion.