The sewage committee of 1864 : and its report as to the purification of river water from town sewage / by Thomas Spencer.

  • Spencer, Thomas.
Date:
1865
Catalogue details

Licence: Public Domain Mark

Credit: The sewage committee of 1864 : and its report as to the purification of river water from town sewage / by Thomas Spencer. Source: Wellcome Collection.

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

    18/42 (page 18)
    The question yet to be determined was, as to the part played by the ozone, in the process of purification, its functions in the economy of nature being not then settled. Ever since this body was observed by Schonbein in, I think, 1839, neither its true nature, nor its functions were thoroughly determined by philoso- phers ; at all events, both were regarded as doubtful. Its dis- coverer had at first set it down as a new elementary body asso- ciated, somehow, with electricity, and occasionally met with in the atmosphere. Since the publication of my experiments in 1857, he seems to recognise the body itself to be polarised oxygen. With regard to its leading function in nature, there is now no room for doubt, that it enters into combination with all noxious organic matters, whether in the atmosphere or in water, and con- verts them into harmless carbonic acid. Subsequent experiments went to show, that the destruction of the organic matter is effected eombustively, by the mere presence of the magnetic body. For example:—Organic matters consist chiefly of hydrated carbonaceous matter, in a species of chemical combination with water. These are constantly liable to putre- factive decomposition, in stagnant or sluggishly flowing water; whence are generated those malarious gases which give to both water and air their unhealthy character. Whenever then, such matter, however noxious, comes in contact with the ozone or even a slight change of colour is observed. For my own part 1 have never seen them, even under favourable circumstances, to be more than slightly blue. At all events, when they become blue in an atmosphere free from acid vapours, ozone is known to be present. It was whilst in search of a mode of proving the nature of the purifying action of the magnetic oxide—believing as I did that ozone was the agent—that it occurred . . ° to me, that if so, it would necessarily change the red guiacum solution into blue. Some was prepared accordingly, and passed through about 10 or 12 ounces of the black oxide obtained from the spathose ore. I do not know that I was ever afforded more real gratification, than when I saw the solution, trickling out of the funnel had assumed — a deep, rich, indigo blue. In this one experiment, more ozone was indicated than a meteorologist could have seen in a lifetime. * Another corroborative experiment was made subsequently by dropping water filtered through the oxide into a starch solution of iodide of potassium—another test for ozone,—which also became faintly blue ; but the former is by far the more striking experiment. In both instances the solutions in time regain their original colour. These experiments were first shown at the meeting of the British Association in 1859.