1873 The Lancet  
other streets in London leads me to bring before your notice my patented Stack-Pipe Watercloset Ventilator. It has been put up in several houses-those of clergymen and medical men,-and in every instance perfectly satisfied all requirements. The novelty of my method is that the ventilation takes place from the very highest point of the sewer (in relation to the house)-viz , the lid of the closet; and, in order to render this perfect, by a mechanical contrivance I prevent the handle being raised,
more » ... andle being raised, and thus the sewer opened, until the lid is hermetically closed on to the seat; sewer gases, which escape when the handle is lifted, and which are constantly being given off from the surface of the water in the pan, pass through the lid ventilator into the open air. It will thus readily be perceived that the closet lid is always hermetically closed on the seat, except when the closet is in actual use. The water in the pans of our waterclosets during this hot weather is always evaporating, and test paper charged with carbonate of lead shows it to be impregnated with sulphuretted hydrogen gas. This gas is conducted into the open air to the top of the house by my contrivance, and if a disinfecting chamber be placed in the pipe all contagion is destroyed. I trust, Sir, that you will feel that my patent is worthy of some consideration from you. Your obedient servant.
doi:10.1016/s0140-6736(02)69411-5 fatcat:ihynefymm5bujezg37gjj5yap4