On the alkaline emanations from sewers and cesspools. / by William Odling.

  • Odling, William, 1829-1921.
Date:
1870
Catalogue details

Licence: Public Domain Mark

Credit: On the alkaline emanations from sewers and cesspools. / by William Odling. 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.

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    dryness. An imperial gallon contained 95*36 grains of solid matter, including 26*28 grains of fixed organic matter. By gently warming another portion of the liquid, there was evolved a considerable amount of permanent gas, consisting principally of carbonic acid; but a little common air and a trace of hydro-sulphuric acid were also present. Half a gallon of the liquid was distilled until the distillate had no longer an alkaline reaction. It had a peculiar fetid ammo- niacal smell. After saturation with hydrochloric acid, it was evaporated to dryness. The residue was dissolved in water, filtered, and precipitated with bichloride of platinum in the usual manner. The platinum salt weighed 58*80 grains, which, supposing it to be the ordinary platino-cliloride of ammonium, would correspond to 8*95 grains of ammonia per gallon. The precipitate was then dissolved in water, and crystallized. The crystals were large and well defined. They occurred as flattened orange-coloured tablets, apparently modified octohedra, but certainly different from the ordinary crystals of platino-chloride of ammonium. A combustion of these crystals was made with chromate of lead. To the combustion tube was attached a U tube containing baryta water, so as to afford visible evidence of the presence of carbonic acid should any be produced. In the course of a few minutes, the baryta water became quite opaque, and so large was the amount of carbonic acid liberated, that the deposit of carbonate of baryta disappeared, owing to its conversion into bicarbonate. The further addition of baryta water reproduced the precipitate, which effervesced readily on the addition of hydrochloric acid. Thus it was rendered evident that the alkaline vapour from the cesspool was not simply ammoniacal, but carbo-ammoniacal. Similar experiments were made with some liquid obtained from a sewer in Griffin Street, York Road, Lambeth. An imperial gallon of the liquid yielded 131*12 grains of solid matter, including 48*96 grains of fixed organic matter. Half a gallon was submitted to distillation. The first portions of the distillate were extremely pungent, and the alkaline reaction continued until nearly all the liquid had passed over. The smell of the distillate corresponded exactly with that of the other specimen. After saturation with hydrochloric acid, and evaporation to dryness, the alkali was precipitated with