Public lecture on "Plumbing and house drainage in relation to public health" / by Neil Carmichael.
- Carmichael, Neil
- Date:
- [1893]
Licence: Public Domain Mark
Credit: Public lecture on "Plumbing and house drainage in relation to public health" / by Neil Carmichael. Source: Wellcome Collection.
Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.
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![tZ suln, *°/epreSent traP3- ^ found that carbonic acui sulphuretted hydrogen, and ammonia, placed in one limb of CUM t' 5T1 'rt ^ the bGnd °f the ^ and ould b detected the airaboye the trapon ^ s.>e from fifteen minutes to three or four hours. When the tubes were ventilated, the time of transmission was slightly increased. These experiments determined the fact that gases could be dissolved by the water in the trap, and be passed out on the other side In these experiments, the gases employed were presented to the surface of the water in a very concentrated condition To wnat extent do the gases and germs of an ordinary soil-pipe pass through the water seal of a sound trap 1 To determine this point l performed a series of experiments in 1878-9. The experiments were performed with an ordinary lead trap connected to a soil- pipe. This soil-pipe was old ; its internal surface was foul ■ into it there discharged three water-closets; it was ventilated above by a two-inch pipe • and it discharged untrapped into the drain The lead pipe on the house side of this trap was closed by soldering on it a plate of zinc, through which passed two smal] lead pipes into the air cavity above the trap. Air of the room, purified from the gases to be tested for, was, by passing it through an absorbing solution (A.P.), drawn continuously by an aspirator through this cavity, and then made to bubble through testing solutions (V1-V6). This was continued for several days at a time, and the experiments were frequently repeated. It was found that, in 24 hours, about 7 grains of carbonic acid passed through the trap, when the ventilator on the roof was open, and that when this was closed about 32 grains passed through. Ammonia passed through from the ventilated pipe to the amount of about ^0fa grain, and, when the ventilator was closed, to the extent of about the Ti„ of a grain. The amount of sulphuretted hydrogen passing through the fcr. p vhen ventilated was about ^ of a grain, when unventilatedf As about ^ of a grain, in 24 hours. Putrid organic vapi /if they passed through, were included in the ammonia, aij^/ere never found to come through the trap in such an amount as to be detectable by smell. As the largest amount of ammonia found to pass through was about of a grain, the putrid organic vapour included in this amount must have been very small indeed. The quantities of injurious gases and vapours,](https://iiif.wellcomecollection.org/image/b2146330x_0012.jp2/full/800%2C/0/default.jpg)
