SEWAGE.

Nelson Evening Mail, Volume VI, Issue 289, 7 December 1871, Page 4

SEWAGE.

The following is from a review in the Medical Times and Gazette, od A Digest of Facts, relating to the Treatment and Utilisation of Sewage, by W. H. Corfield, M.A., Professor of Public Health at University College, London. It will be found to contain matter of interest to residents in this town :— That a second edition of Professor Corfield's work on Sewage has been demanded in so short a time proves that the interest of the public in its subject is greater than that excited by most works on sauitary matters. Wealth is of the first consideration in England, health of the second ; and as the utilisation of sewage certainly signifies wealth, whilst its treatment has a definite bearing on health, the public iv their anxiety for the former probably do not object to obtain with it some information on the latter- Dr. Corfield's work is a ver*y elabora» treatise. We can recommend it to our readers as containing a large amount of information and some able reasoning. We cannot, however, attempt an extended review of its contents; but this is not necessary, as Dr.' Corfield's conclusion;*, have been summed up ready to oar-Muds at the termination of hi work* author lays down the obrioii

principle " that the method which does, in practice, when it is anything like efficiently carried ont, remove at once and completely from the vicinity of habitations the various sorts of refuse in the most expeditious manner, is the one which must be the most conducive to health." From his premises ho draws the conclusion that all dry methods of treating sewage violate this principle—that they leave the excremeutal matters iv and about the house too long. Even the dry earth system is open to this objection. "Although it has been shown to have a great advantage when it has replaced midden-heaps and cesspools, we maintain, with Dr. Rollestoii aud with Dr. Parkes, that it has not been shown that the compost is disinfected as well as deodorised." Dr. Corfield urges that the deodorisation alone of a noxious compound only renders it more dangerous. If coal-gas were deodorised, accidents would be more numerous. Carbonic oxide, the most poisonous ingredient of coal-gas, the emanations of typhus fever, are odourless. It is only a presumption that all danger from the noxious emanations of exeretnentitious matter is removed by mixing ifc with earth. Then, als'->, there is the objection that, if the Earth were supplied in too small quantity, too moist, or of bad quality, or the air being very damp, or the compost wetted through carlesness or otherwise, danger of infection would at once ntis- j . The author concludes, with Miss Nightingale, that " the true k j y to sanitary progress in cities is, water-supply and sewerage. No city can be purified sufficiently by mere hand-labor in (etching aud carrying." The results of the watercarriage system, the author 'believes,' despite of its disadvantnges, to be unapproachable by other modes of treatment. He traces to it, in conjunction with other sanitary improvements, in certaiu to'vos the practical annihilation of cholera, and the extermination of typhoid. "We are sure that it is the speedy removal of the refuse mutters that has accomplished this; because, in towns where free exit has not been allowed for the sewage from the sewers, the death-rate of typhoid fever has only very slightly diminished, or has slightly increased, or even (in one case) has very considerably increased." The mortality of pithisis, the author also finds, has been diminished by the construction of deep-drain sewers ; in one case the diminution has amounted to nearly half the former number of deaths. A waterlogged subsoil is a potent cause of phthisis —a fact which suggests the necessity of impervious pipe sewers. How, then, is the sewage to be disposed of ? After discussing the relative advantages of filtration, precipitation, and irrigation! Ihe author finds that irrigative farming alone fulfils the three conditions of purifying the Be\v.ige, iusuring a profitable agricultural return, and not endangering the health of the neighbornood. Iv conclusion, he writes— " We are, then, reduced to tlm Hi 1 lowing simple issue : wherever it is possible, irrigation should be carried out, the sewage having been previously freed, by one or other of the methods described, from the offensive suspended matters, which must be deodorised to prevent the production of a serious uuisance. Whereever, ou the other hand, irrigation is practically impossible, intermittent downward filtration, through, soil or other suitable material, affordsj the means of satisfactorily purifyiug the sewage."