On sewage treatment and disposal : for cities, towns, villages, private dwellings, and public institutions / by Thomas Wardle.

Date:
[1893]
Catalogue details

Licence: Public Domain Mark

Credit: On sewage treatment and disposal : for cities, towns, villages, private dwellings, and public institutions / by Thomas Wardle. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    55/482 (page 19)
    Bacteria. 29 Nine of these species were found to convert nitrates into nitrites, some with great completeness and rapidity. The species which failed to reduce nitrates were Bac. superficialis, Bac. rubescens, and P. Zenkeri. Wherever dead organic materials, excreta of man and animals, dead bodies, dead plants, household refuse, &c., accumulate on the surface of the ground, in stagnant or running water, or within dwelling-houses, in the presence of sufficient moisture and temperature, bacterial growth occurs, and ulti- mately occasions the complete destruction of these materials, the place of which is taken by an enormous number of newly- formed individuals.* The refuse of houses and of cattle stalls forms also a favour- able place for the accumulation of bacteria. The intestinal excreta contain at times infective agents mixed with the lar^e numbers of saprophytes; for example, typhoid bacilli, cholera bacilli, tubercle bacilli, anthrax bacilli, the bacilli of swine fever, of chicken cholera, «fec.; further, probably the infective agents of dysentery and of the epidemic diarrhoea of children.! Turning now from American investigations, interesting as they prove to be, I will enumerate those bacteria which chiefly play such a harmful part in the economy of animal life, both in man and in the lower animals, namely, the pathogenic, or those associated with disease, and it will be instructive, and I hope helpful, if I illustrate this part of the chapter as fully as the present state of this branch of natural history permits. I will also include a few forms which are saprophytic but unassociated with disease, but which play a great part as the burners and buriers of dead organic matter, and I hope the addition of one or two additional plates on this subject will emphasise the importance which I believe ought to attach to it in connection with sewage treatment and disposal, and disarm a criticism ' Flilgge's Mlcro-organiBms, p. 689. ■t Jbid., p. 720,